docs(spec): amend Spec 049 — legalize server_quarantined status (six-value taxonomy)

Aligns Spec 049 with PR #778, which adds a sixth disabled-tool status,
server_quarantined, surfaced by a dedicated quarantined-tool discovery pass
(quarantined tools are deliberately excluded from the search index as a TPA
defense). Spec 049 pinned the taxonomy to exactly five values and assumed all
locked tools live in the index, so #778's behavior was correct but undocumented.

- FR-004: five -> six values; server_quarantined assigned by the discovery pass
  (not the classifier), name-only, description/schema withheld; config-denied
  tools skipped by the pass.
- FR-003: note the name-only exception for quarantined entries.
- Assumptions: quarantined tools are excluded from the index and enumerated from
  authoritative quarantine state.
- contracts/mcp-deltas.md: add server_quarantined to the status enum + example
  response shape and remediation.
- design doc taxonomy: five -> six, with the server_quarantined explanation.

Related #778

Author: Algis Dumbris

docs/superpowers/specs/2026-05-18-agent-discoverable-disabled-tools-design.md

@@ -91,7 +91,8 @@ not exercised.
 
 ### 4.3 Status taxonomy & classification
 
-`status` is one of five values. Classification order is **first match wins**:
+`status` is one of six values. The first five are classifier-assigned to
+index-discoverable tools; classification order is **first match wins**:
 
 | Order | Condition | `status` | `remediation` text (emitted once if present) |
 |------|-----------|----------|----------------------------------------------|
@@ -105,6 +106,17 @@ not exercised.
 *wrong* remediation (e.g. telling the user to toggle a UI switch for a
 config-locked tool). The four happy-path states stay clean.
 
+The sixth value, `server_quarantined`, is **not** classifier-assigned: quarantined
+tools are deliberately absent from the search index (their untrusted descriptions
+are withheld as a Tool Poisoning Attack defense), so the index loop cannot reach
+them. A dedicated discovery pass enumerates them from authoritative quarantine
+state and emits **name-only** locked entries — a tool on a quarantined server gets
+`server_quarantined`; a tool-level pending/changed approval on a trusted server
+re-uses `pending_approval`. A tool also denied by operator config is skipped
+(approval could not make it callable). Remediation for `server_quarantined`: "Its
+server is quarantined for security review. Its tools cannot be called until the
+user reviews and approves the server in the mcpproxy UI or system tray."
+
 ### 4.4 Reactive triggers (discoverability)
 
 Option C's only weakness is the agent not knowing the flag exists. Closed two ways:

specs/049-agent-discoverable-disabled-tools/contracts/mcp-deltas.md

@@ -24,14 +24,27 @@ Tool description gains exactly one sentence (FR-014):
   "tools": [ /* callable results — UNCHANGED order/shape (FR-002, FR-006) */ ],
   "disabled": [                                  // NEW, after callable, ≤ min(limit,10)
     { "name": "delete_repo", "server": "github",
-      "description": "Delete a repository", "status": "disabled_by_config" }
+      "description": "Delete a repository", "status": "disabled_by_config" },
+    // Quarantined-tool discovery pass: name-only, description/schema withheld
+    // (TPA defense); `name` is the "<server>:<tool>" key. Prepended ahead of
+    // index-derived locked entries so the min(limit,10) cap can't drop them.
+    { "name": "github:rotate_keys", "server": "github",
+      "status": "server_quarantined" }
   ],
   "remediation": {                               // NEW, once, only present statuses
-    "disabled_by_config": "Locked by operator policy in mcp_config.json (enabled_tools/disabled_tools). The user cannot enable this from the UI; ask the operator to change the server config."
+    "disabled_by_config": "Locked by operator policy in mcp_config.json (enabled_tools/disabled_tools). The user cannot enable this from the UI; ask the operator to change the server config.",
+    "server_quarantined": "Its server is quarantined for security review. Its tools cannot be called until the user reviews and approves the server in the mcpproxy UI or system tray."
   }
 }
 ```
 
+`status` enum (FR-004): `disabled_by_config`, `disabled_by_user`,
+`pending_approval`, `server_disabled`, `disabled_unknown`, `server_quarantined`.
+The first five are classifier-assigned to index-discoverable tools; the last is
+assigned by the quarantined-tool discovery pass (also re-using `pending_approval`
+for tool-level pending/changed approvals), which surfaces name-only entries from
+authoritative quarantine state because quarantined tools are not in the index.
+
 ### Response delta (0 callable results, ≥1 locked match, flag OFF) — FR-009
 
 A one-line note added to the existing result text:

specs/049-agent-discoverable-disabled-tools/spec.md

@@ -120,11 +120,23 @@ callable one carries none.
   fields, no reordering).
 - **FR-003**: Each returned locked tool MUST carry a lean shape: name, owning
   server, the existing one-line description, and a single `status` value.
-- **FR-004**: `status` MUST be one of exactly five values —
+  Exception: a `server_quarantined` entry (and any tool surfaced by the
+  quarantined-tool discovery pass) withholds the description and schema, so it
+  carries name + owning server + `status` only.
+- **FR-004**: `status` MUST be one of exactly six values —
   `disabled_by_config`, `disabled_by_user`, `pending_approval`,
-  `server_disabled`, `disabled_unknown` — assigned by fixed first-match
-  precedence in that order (server-off, then config, then user-disabled, then
-  pending approval, else unknown).
+  `server_disabled`, `disabled_unknown`, `server_quarantined`. The first five
+  are assigned to index-discoverable tools by fixed first-match precedence in
+  that order (server-off, then config, then user-disabled, then pending
+  approval, else unknown). `server_quarantined` is assigned separately by the
+  quarantined-tool discovery pass (not the classifier), because quarantined
+  tools are deliberately absent from the search index (see Assumptions): it
+  covers a tool on a quarantined server (status `server_quarantined`) and a
+  tool-level pending/changed approval on a trusted server (status
+  `pending_approval`), with description and schema withheld to avoid exposing a
+  Tool Poisoning Attack payload. A tool also denied by operator config
+  (`enabled_tools`/`disabled_tools`) is skipped by this pass rather than
+  surfaced, since approval could not make it callable.
 - **FR-005**: The response MUST include a single remediation map emitted once,
   containing only the keys for statuses actually present in the response; no
   per-tool remediation text.
@@ -154,7 +166,8 @@ callable one carries none.
 ### Key Entities *(include if feature involves data)*
 
 - **Locked tool entry**: A discovered tool that is not callable — name, server,
-  one-line description, and one `status` of the five-value set.
+  one-line description (withheld for quarantined entries), and one `status` of
+  the six-value set.
 - **Status**: The single machine-branchable reason a tool is not callable,
   mapped 1:1 to a remediation class.
 - **Remediation map**: Response-level mapping from each present status to one
@@ -185,7 +198,13 @@ callable one carries none.
 
 - Locked tools are present in the existing search index (verified during
   brainstorming: indexing does not filter by callability; filtering is
-  request-time only).
+  request-time only). Exception: quarantined tools — both on a quarantined
+  server and tool-level pending/changed approvals — are deliberately excluded
+  from the search index so their untrusted descriptions cannot be ranked or
+  exposed (Tool Poisoning Attack defense). They are therefore not reachable via
+  the index loop and are instead enumerated from authoritative quarantine state
+  by a dedicated discovery pass that emits name-only `server_quarantined` /
+  `pending_approval` entries.
 - The config-vs-user discriminator introduced by PR #468 is available and is
   reused unchanged as the authoritative config-denial signal.
 - "Limit" refers to the discovery request's existing result-limit parameter.