Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the sparse annotations, the description discloses key behaviors: invoke runs a tool one-off without installing, may return connect/checkout links requiring user action then retry, and writes require owner/admin. It also notes search/describe flag installed_in_toolkit vs installed_in_workspace. No contradiction with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is dense but front-loaded: it starts with the tool's role, then core flow, key behaviors, install vs invoke, and prompt library. Each section contributes, but it is a long paragraph that could be more scannable with bullets. Still, every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with 14 actions and 23 parameters, the description covers the major flows, edge cases (auth, payment, permissions), and the secondary prompt library. It doesn't specify exact output shapes for each action, but it explains key outputs like connect links, checkout links, and shareable prompt links. Given the absence of an output schema, this is fairly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema description coverage, the description compensates by explaining the action enum values (search, describe, invoke, install, list_tools, prompt actions), the meaning of tool_id and arguments, and the prompt library parameters. However, several params (limit, query, immediate, tier_slug, cancel_comment, etc.) are not individually explained, though their context is implied by action names.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool is 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them,' which is a specific role. It describes the core search→describe→invoke flow and distinguishes itself from sibling tools (e.g., authenticate, connect) by focusing on discovery and execution of MCPs.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly provides decision rules: 'Use install only to make an MCP PERMANENT... prefer invoke for a single/occasional use,' 'If the MCP needs a credential/login, invoke returns a connect link... then you retry,' and 'request_mcp asks us to build a NEW MCP when nothing fits.' It also states write operations require workspace owner/admin, giving clear when-to-use and when-not guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.