The server defines 6 tools with explicit FastMCP @mcp.tool() registration and visible input schemas. Tool names follow verb-noun conventions (gemini_prompt, gemini_version, gemini_mcp_list, gemini_mcp_add, gemini_mcp_remove, gemini_web_fetch). However, descriptions are present but minimal (18 - 80 chars, averaging ~45 chars), falling below the 194-char production baseline. All tools have input schemas with type definitions and descriptions for parameters, meeting the schema baseline. Output is uniformly returned as JSON strings rather than structured objects, limiting downstream composition. Error handling is basic (RuntimeError on non-zero exit, but no recovery guidance or actionable messages for LLMs). Tool composition is reasonable, each has a single responsibility, but the return format (always JSON-stringified) makes it hard for agents to extract and chain results without re-parsing. Security: credentials are passed as parameters (see gemini_mcp_add with headers, env_vars) rather than server-side injection, violating pattern:secret-injection. No permission gates, scope declarations, or audit trails. SSRF mitigation present (_is_private_url) is a positive.

• Expand each tool description to 100 - 250 characters. Include WHAT it does, WHEN to use it, and key prerequisites. Example: 'Run a prompt against the local gemini CLI non-interactively. Use this to execute LLM queries with local context files. Requires gemini CLI installed and configured. Returns structured JSON with exit code and output.'
• Move env_vars and headers from parameters to server-side configuration. Read them from environment variables or a secure vault on startup, never expose them as tool parameters.
• Return structured objects instead of JSON-stringified strings. Have _run_gemini_and_format_output return a dict with 'ok', 'exit_code', 'stdout', 'stderr' keys directly, not as a JSON string. Let FastMCP serialize to the protocol.
• Add actionable error messages. On non-zero exit, return a message like: 'Command failed with exit code 1. stderr: <msg>. If gemini CLI not found, run: brew install gemini (macOS) or apt install gemini (Linux).'
• Add tool annotations. Use destructiveHint=true for gemini_mcp_remove; readOnlyHint=true for gemini_prompt, gemini_version, gemini_mcp_list, gemini_web_fetch; idempotentHint=true if applicable.
• Document parameter dependencies. In gemini_mcp_add description, clarify: 'For stdio transport, pass executable in command_or_url and omit headers. For http/sse, pass URL and may include headers. Args and env_vars apply to all transports.'
• Add minimum/maximum constraints to timeout_s. Document: 'Timeout in seconds, between 1 and 3600. Defaults to env GEMINI_BRIDGE_DEFAULT_TIMEOUT_S or 120 seconds.'