fix(fetch): use inclusive minimum/maximum instead of exclusive bounds in schema

The Fetch model used gt=0 and lt=1000000 Pydantic constraints on
max_length, which generates exclusiveMinimum/exclusiveMaximum in the
JSON Schema. Some LLM providers (e.g. Google Gemini 2.5) only support
OpenAPI 3.0 schema keywords and reject these with a 400 error.

Switch to ge=1 / le=999999 (identical semantics for integers) so Pydantic
emits the universally supported minimum/maximum keywords instead.

Fixes #1624

Made-with: Cursor

Author: dhshah13

src/fetch/src/mcp_server_fetch/server.py

@@ -157,8 +157,8 @@ class Fetch(BaseModel):
         Field(
             default=5000,
             description="Maximum number of characters to return.",
-            gt=0,
-            lt=1000000,
+            ge=1,
+            le=999999,
         ),
     ]
     start_index: Annotated[

src/fetch/tests/test_server.py

@@ -5,6 +5,7 @@
 from mcp.shared.exceptions import McpError
 
 from mcp_server_fetch.server import (
+    Fetch,
     extract_content_from_html,
     get_robots_txt_url,
     check_may_autonomously_fetch_url,
@@ -13,6 +14,24 @@
 )
 
 
+class TestFetchToolSchema:
+    """Tests for the Fetch model JSON schema compatibility."""
+
+    def test_schema_uses_inclusive_bounds(self):
+        """Ensure the schema uses minimum/maximum instead of exclusiveMinimum/exclusiveMaximum.
+
+        Some LLM providers (e.g. Google Gemini) only support OpenAPI 3.0
+        schema keywords and reject exclusiveMinimum/exclusiveMaximum.
+        """
+        schema = Fetch.model_json_schema()
+        max_length_schema = schema["properties"]["max_length"]
+
+        assert "exclusiveMinimum" not in max_length_schema
+        assert "exclusiveMaximum" not in max_length_schema
+        assert max_length_schema["minimum"] == 1
+        assert max_length_schema["maximum"] == 999999
+
+
 class TestGetRobotsTxtUrl:
     """Tests for get_robots_txt_url function."""