Add dedicated git tool with condensed prompt, reducing per-turn token overhead

🤖 Generated with [eca](https://eca.dev)

Co-Authored-By: eca <git@eca.dev>

Author: ericdallo

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Show the selected `variant` in `spawn_agent` subagent details and harden restrictions regarding the use of the optional model in sub-agent. #369
 - Fix MCP OAuth browser not opening on Windows by using `cmd /c start` instead of `java.awt.Desktop`, which is unavailable in the native image.
 - Improve server shutdown speed for remote MCP servers.
+- Extract git/gh instructions from `shell_command` into a dedicated `git` tool with a condensed prompt, reducing per-turn token overhead.
 
 ## 0.117.1
 

resources/prompts/tools/git.md

@@ -0,0 +1,53 @@
+Runs git and gh (GitHub CLI) commands.
+
+Always provide the `operation` that best describes what the command does.
+Provide a concise `summary` (2-3 words) of what is being done.
+
+# Commits
+
+1. First run: `git status`, `git diff` (staged + unstaged), `git log` (for commit style).
+2. Analyze: files changed, nature/purpose, sensitive info check, draft a "why"-focused message.
+3. Stage only relevant files (avoid blind `git add .`), then commit via HEREDOC:
+
+<example>
+git commit -m "$(cat <<'EOF'
+Commit message here.
+
+🤖 Generated with [eca](https://eca.dev)
+
+Co-Authored-By: eca <git@eca.dev>
+EOF
+)"
+</example>
+
+4. If pre-commit hooks modify files, amend or retry ONCE. If it fails again, stop.
+
+# Pull Requests
+
+1. First run: `git status`, `git diff`, `git log`, `git diff main...HEAD` to review ALL commits since diverging.
+2. Analyze: all commits (not just latest), nature/purpose/impact, draft 1-3 bullet summary.
+3. Push with `-u` if needed, then create PR via HEREDOC:
+
+<example>
+gh pr create --title "the pr title" --body "$(cat <<'EOF'
+## Summary
+<1-3 bullet points>
+
+## Test plan
+[Testing checklist]
+
+🤖 Generated with [eca](https://eca.dev)
+EOF
+)"
+</example>
+
+4. Return the PR URL.
+
+# Rules
+- Never use interactive flags (`-i`, `--interactive`)
+- Never update git config
+- Do not push unless creating a PR
+- Do not create empty commits
+- Always use HEREDOC for multi-line messages
+- Use `gh` for all GitHub API interactions (issues, PRs, checks, releases)
+- Given a GitHub URL, use `gh` to fetch the information

resources/prompts/tools/shell_command.md

@@ -28,110 +28,3 @@ Usage notes:
     <bad-example>
     cd /foo/bar && pytest tests
     </bad-example>
-
-# Committing changes with git
-
-When the user asks you to create a new git commit, follow these steps carefully:
-
-1.:
-   - Run a git status command to see all untracked files.
-   - Run a git diff command to see both staged and unstaged changes that will be committed.
-   - Run a git log command to see recent commit messages, so that you can follow this repository's commit message style.
-
-2. Analyze all staged changes (both previously staged and newly added) and draft a commit message. Wrap your analysis process in <commit_analysis> tags:
-
-<commit_analysis>
-- List the files that have been changed or added
-- Summarize the nature of the changes (eg. new feature, enhancement to an existing feature, bug fix, refactoring, test, docs, etc.)
-- Brainstorm the purpose or motivation behind these changes
-- Assess the impact of these changes on the overall project
-- Check for any sensitive information that shouldn't be committed
-- Draft a concise (1-2 sentences) commit message that focuses on the \"why\" rather than the \"what\"
-- Ensure your language is clear, concise, and to the point
-- Ensure the message accurately reflects the changes and their purpose (i.e. \"add\" means a wholly new feature, \" update \" means an enhancement to an existing feature, \"fix\" means a bug fix, etc.)
-- Ensure the message is not generic (avoid words like \"Update\" or \"Fix\" without context)
-- Review the draft message to ensure it accurately reflects the changes and their purpose
-</commit_analysis>
-
-3.:
-   - Add relevant untracked files to the staging area.
-   - Create the commit with a message ending with:
-   🤖 Generated with [eca](https://eca.dev)
-
-   Co-Authored-By: eca <noreply@eca.dev>
-   - Run git status to make sure the commit succeeded.
-
-4. If the commit fails due to pre-commit hook changes, retry the commit ONCE to include these automated changes. If it fails again, it usually means a pre-commit hook is preventing the commit. If the commit succeeds but you notice that files were modified by the pre-commit hook, you MUST amend your commit to include them.
-
-Important notes:
-- Use the git context at the start of this conversation to determine which files are relevant to your commit. Be careful not to stage and commit files (e.g. with `git add .`) that aren't relevant to your commit.
-- NEVER update the git config
-- DO NOT run additional commands to read or explore code, beyond what is available in the git context
-- DO NOT push to the remote repository
-- IMPORTANT: Never use git commands with the -i flag (like git rebase -i or git add -i) since they require interactive input which is not supported.
-- If there are no changes to commit (i.e., no untracked files and no modifications), do not create an empty commit
-- Ensure your commit message is meaningful and concise. It should explain the purpose of the changes, not just describe them.
-- Return an empty response - the user will see the git output directly
-- In order to ensure good formatting, ALWAYS pass the commit message via a HEREDOC, a la this example:
-<example>
-git commit -m \"$(cat <<'EOF'
-   Commit message here.
-
-   🤖 Generated with [eca](https://eca.dev)
-
-   Co-Authored-By: eca <noreply@eca.dev>
-   EOF
-   )\"
-</example>
-
-# Creating pull requests
-Use the gh command via the Bash tool for ALL GitHub-related tasks including working with issues, pull requests, checks, and releases. If given a Github URL use the gh command to get the information needed.
-
-IMPORTANT: When the user asks you to create a pull request, follow these steps carefully:
-
-1. In order to understand the current state of the branch since it diverged from the main branch:
-   - Run a git status command to see all untracked files
-   - Run a git diff command to see both staged and unstaged changes that will be committed
-   - Check if the current branch tracks a remote branch and is up to date with the remote, so you know if you need to push to the remote
-   - Run a git log command and `git diff main...HEAD` to understand the full commit history for the current branch (from the time it diverged from the `main` branch)
-
-2. Analyze all changes that will be included in the pull request, making sure to look at all relevant commits (NOT just the latest commit, but ALL commits that will be included in the pull request!!!), and draft a pull request summary. Wrap your analysis process in <pr_analysis> tags:
-
-<pr_analysis>
-- List the commits since diverging from the main branch
-- Summarize the nature of the changes (eg. new feature, enhancement to an existing feature, bug fix, refactoring, test, docs, etc.)
-- Brainstorm the purpose or motivation behind these changes
-- Assess the impact of these changes on the overall project
-- Do not use tools to explore code, beyond what is available in the git context
-- Check for any sensitive information that shouldn't be committed
-- Draft a concise (1-2 bullet points) pull request summary that focuses on the \"why\" rather than the \"what\"
-- Ensure the summary accurately reflects all changes since diverging from the main branch
-- Ensure your language is clear, concise, and to the point
-- Ensure the summary accurately reflects the changes and their purpose (ie. \"add\" means a wholly new feature, " update " means an enhancement to an existing feature, \"fix\" means a bug fix, etc.)
-- Ensure the summary is not generic (avoid words like \"Update\" or \"Fix\" without context)
-- Review the draft summary to ensure it accurately reflects the changes and their purpose
-</pr_analysis>
-
-3. ALWAYS run the following commands in parallel:
-   - Create new branch if needed
-   - Push to remote with -u flag if needed
-   - Create PR using gh pr create with the format below. Use a HEREDOC to pass the body to ensure correct formatting.
-<example>
-gh pr create --title \"the pr title\" --body \"$(cat <<'EOF'
-## Summary
-<1-3 bullet points>
-
-## Test plan
-[Checklist of TODOs for testing the pull request...]
-
-🤖 Generated with [eca](https://eca.dev)
-EOF
-)\"
-</example>
-
-Important:
-- NEVER update the git config
-- Return the PR URL when you're done, so the user can see it
-
-# Other common operations
-- View comments on a Github PR: gh api repos/foo/bar/pulls/123/comments

src/eca/config.clj

@@ -97,7 +97,7 @@
                    :disabledTools ["preview_file_change"]}
            "plan" {:mode "primary"
                    :prompts {:chat "${classpath:prompts/plan_agent.md}"}
-                   :disabledTools ["edit_file" "write_file" "move_file"]
+                   :disabledTools ["edit_file" "write_file" "move_file" "git"]
                    :toolCall {:approval {:byDefault "ask"
                                          :allow {"eca__shell_command"
                                                  {:argsMatchers {"command" ["pwd"
@@ -120,7 +120,7 @@
            "explorer" {:mode "subagent"
                        :description "${classpath:prompts/explorer_agent_description.md}"
                        :systemPrompt "${classpath:prompts/explorer_agent.md}"
-                       :disabledTools ["edit_file" "write_file" "move_file" "preview_file_change"]
+                       :disabledTools ["edit_file" "write_file" "move_file" "preview_file_change" "git"]
                        :toolCall {:approval {:byDefault "ask"
                                              :allow {"eca__shell_command"
                                                      {:argsMatchers {"command" ["pwd"

src/eca/features/tools.clj

@@ -9,6 +9,7 @@
    [eca.features.tools.custom :as f.tools.custom]
    [eca.features.tools.editor :as f.tools.editor]
    [eca.features.tools.filesystem :as f.tools.filesystem]
+   [eca.features.tools.git :as f.tools.git]
    [eca.features.tools.mcp :as f.mcp]
    [eca.features.tools.mcp.clojure-mcp]
    [eca.features.tools.shell :as f.tools.shell]
@@ -153,6 +154,7 @@
    (merge {}
           f.tools.filesystem/definitions
           f.tools.shell/definitions
+          f.tools.git/definitions
           f.tools.editor/definitions
           f.tools.chat/definitions
           f.tools.skill/definitions
@@ -167,9 +169,10 @@
   "Filter tools for subagent execution.
 
    - Excludes spawn_agent to prevent nesting.
-   - Excludes task because task list state is currently chat-local; it should be managed by the parent agent."
+   - Excludes task because task list state is currently chat-local; it should be managed by the parent agent.
+   - Excludes git because subagents don't perform git operations."
   [tools]
-  (filterv #(not (contains? #{"spawn_agent" "task"} (:name %))) tools))
+  (filterv #(not (contains? #{"spawn_agent" "task" "git"} (:name %))) tools))
 
 (defn all-tools
   "Returns all available tools, including both native ECA tools

src/eca/features/tools/git.clj

@@ -0,0 +1,111 @@
+(ns eca.features.tools.git
+  (:require
+   [babashka.process :as p]
+   [clojure.string :as string]
+   [eca.features.tools.shell :as shell]
+   [eca.features.tools.util :as tools.util]
+   [eca.logger :as logger]
+   [eca.shared :as shared]))
+
+(set! *warn-on-reflection* true)
+
+(def ^:private logger-tag "[TOOLS-GIT]")
+
+(def ^:private default-timeout 120000)
+
+(defn ^:private git-command [arguments {:keys [db tool-call-id call-state-fn state-transition-fn]}]
+  (let [command (get arguments "command")]
+    (or (tools.util/invalid-arguments
+         arguments
+         [["command" #(and (string? %)
+                          (let [trimmed (string/triml %)
+                                cmd (if (string/starts-with? trimmed "cd ")
+                                      (or (some->> (re-find #"^cd\s+\S+\s*(?:&&|;)\s*(.*)" trimmed)
+                                                   second
+                                                   string/triml)
+                                          trimmed)
+                                      trimmed)]
+                            (or (string/starts-with? cmd "git ")
+                                (string/starts-with? cmd "git;")
+                                (string/starts-with? cmd "gh "))))
+           "command must start with 'git' or 'gh' (optionally preceded by 'cd <path> &&')"]])
+        (let [work-dir (or (some-> (:workspace-folders db)
+                                   first
+                                   :uri
+                                   shared/uri->filename)
+                           (System/getProperty "user.home"))
+              _ (logger/debug logger-tag "Running command:" command)
+              result (try
+                       (if-let [proc (when-not (= :stopping (:status (call-state-fn)))
+                                       (shell/start-shell-process! {:cwd work-dir
+                                                                    :script command}))]
+                         (do
+                           (state-transition-fn :resources-created {:resources {:process proc}})
+                           (try (deref proc default-timeout ::timeout)
+                                (catch InterruptedException e
+                                  (let [msg (or (.getMessage e) "Git tool call was interrupted")]
+                                    (logger/debug logger-tag "Git tool call was interrupted"
+                                                  {:tool-call-id tool-call-id :message msg})
+                                    (tools.util/tool-call-destroy-resource! "eca__git" :process proc)
+                                    (state-transition-fn :resources-destroyed {:resources [:process]})
+                                    {:exit 1 :err msg}))))
+                         {:exit 1 :err "Tool call is :stopping, so process not spawned"})
+                       (catch Exception e
+                         (let [msg (or (.getMessage e) "Caught an Exception during execution of the git tool")]
+                           (logger/warn logger-tag "Got an Exception during execution" {:message msg})
+                           {:exit 1 :err msg}))
+                       (finally
+                         (let [state (call-state-fn)]
+                           (when-let [resources (:resources state)]
+                             (doseq [[res-kwd res] resources]
+                               (tools.util/tool-call-destroy-resource! "eca__git" res-kwd res))
+                             (when (#{:executing :stopping} (:status state))
+                               (state-transition-fn :resources-destroyed {:resources (keys resources)}))))))]
+          (if (= result ::timeout)
+            (do
+              (logger/debug logger-tag "Command timed out after" default-timeout "ms")
+              (tools.util/single-text-content (str "Command timed out after " default-timeout " ms") true))
+            (do
+              (logger/debug logger-tag "Command executed:" result)
+              {:error (not (zero? (:exit result)))
+               :contents (remove nil?
+                                 (concat [{:type :text
+                                           :text (str "Exit code: " (:exit result))}]
+                                         (when-not (string/blank? (:err result))
+                                           [{:type :text
+                                             :text (str "Stderr:\n" (string/trim (:err result)))}])
+                                         (when-not (string/blank? (:out result))
+                                           [{:type :text
+                                             :text (str "Stdout:\n" (string/trim (:out result)))}])))}))))))
+
+(defn ^:private git-command-summary [{:keys [args]}]
+  (let [operation (get args "operation")
+        summary (get args "summary")]
+    (if operation
+      (cond-> (str "Git " operation)
+        summary (str ": " summary))
+      "Preparing git operation")))
+
+(def definitions
+  {"git"
+   {:description (tools.util/read-tool-description "git")
+    :parameters {:type "object"
+                 :properties {"command" {:type "string"
+                                         :description "The git or gh command to execute."}
+                              "operation" {:type "string"
+                                           :description "The git operation being performed."
+                                           :enum ["status" "diff" "log" "add" "commit" "push"
+                                                  "branch" "checkout" "merge" "rebase" "stash"
+                                                  "pr_create" "pr_view" "pr_comment" "gh_other"]}
+                              "summary" {:type "string"
+                                         :description "Concise 2-3 word description of what is being done (e.g. \"staged changes\", \"all test files\")."}}
+                 :required ["command" "operation"]}
+    :handler #'git-command
+    :summary-fn #'git-command-summary}})
+
+(defmethod tools.util/tool-call-destroy-resource! :eca__git [name resource-kwd resource]
+  (logger/debug logger-tag "About to destroy resource" {:resource-kwd resource-kwd})
+  (case resource-kwd
+    :process (p/destroy-tree resource)
+    (logger/warn logger-tag "Unknown resource keyword" {:tool-name name
+                                                        :resource-kwd resource-kwd})))