GCP MCP server has 8 well-named tools covering GCP services (Resource Manager, Compute Engine, Cloud Storage). Tool names follow verb_noun convention consistently (list_projects, get_project, start_instance, stop_instance). Descriptions are present for all tools and most are 50-200 characters, matching LLM-optimized baseline. However, critical gaps exist: (1) parameter descriptions are sparse or missing in 6 of 8 tools; (2) output schemas are not documented, callers don't know what fields to expect; (3) error handling is minimal (raw exceptions, no recovery guidance); (4) no input validation documentation; (5) no pagination support despite list_ tools that could return many items. The code shows good implementation (async/await, proper exception types like NotFoundError, lifespan context), but tool definitions lack the detail needed for reliable LLM invocation.

• Add output schema documentation to every tool. For each tool, document the structure of the return value (e.g., list_projects returns List[{project_id: str, name: str, state: str, parent: str}]). Use JSON Schema format or plain-language field descriptions.
• Add descriptions to all input parameters. For list_instances, expand zone description from current text to: 'The GCP zone (e.g., us-central1-a). If omitted, returns an aggregated list across all zones in the project.'
• Add pagination parameters to list_ tools. Modify list_projects, list_service_accounts, list_instances, and list_buckets to accept limit (1-100, default 20) and offset/page_token parameters. Return a total_count or next_cursor in the response.
• Enhance error messages with recovery guidance. Catch NotFoundError in get_project and suggest 'Try calling list_projects() to see available project IDs.' Similarly, for list_service_accounts, suggest 'Try get_project() to verify the project exists.'
• Document idempotency for start_instance and stop_instance. Add a note to the tool description: 'Idempotent: calling start_instance on an already-running instance succeeds without side effects.' (If true; if false, explicitly state the failure mode.)
• Add tool annotations (readOnlyHint, destructiveHint, idempotentHint) for write-risk tools. Mark start_instance and stop_instance with destructiveHint=true so agents can reason about blast radius.
• Document parameter constraints inline. For project_id, add: '6-30 lowercase alphanumeric characters and hyphens (e.g., my-project-123).' For zone, add enum of valid zones or format pattern.

Inferred effective spec: <=2025-11-25.

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry