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

The description discloses key behaviors beyond annotations: 'invoke works even when the MCP is NOT installed — it runs the tool pontualmente, without adding the MCP to the toolkit,' 'Writes (install/uninstall/subscribe/cancel and the one-off install behind invoke) require workspace owner/admin,' and explains what happens when credentials are needed or wallet is empty. This is far richer than the minimal annotation hints.

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 long but information-dense, with every sentence adding meaningful context. It is structured around a core flow and then expands to edge cases and the prompt library. While it could benefit from bullet points, the front-loaded purpose and organized content make it easy to navigate.

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?

Given the tool's high complexity (15 actions, 23 params, no output schema), the description covers the main flows, auth/billing behavior, and prompt library well. However, some actions like 'resume' and 'list_tools' are only mentioned, not explained, and return shapes for core actions like search/describe are omitted. It is a strong but not exhaustive effort.

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 coverage, the description must compensate and largely does: it explains the meaning of the action parameter ('action=search discovers MCPs by intent → describe returns one MCP's full profile... invoke RUNS that tool'), and mentions mcp_id, tool_id, and prompt_* parameters in context. However, many parameters like limit, query, immediate, tier_slug, and conversation are not explicitly explained, leaving some ambiguity.

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 identifies the tool as 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It specifies the core flow (search → describe → invoke) and the tool's role in discovering and running MCPs, distinguishing it from sibling tools which are specific 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?

The description offers explicit guidance on when to use each action: 'prefer invoke for a single/occasional use,' 'Use install only to make an MCP PERMANENT in the active toolkit,' and explains when to use search vs describe vs invoke. It also notes write permission requirements and how to handle auth/payment links.

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