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

Annotations are minimal (readOnlyHint=false, destructiveHint=false), but the description adds rich behavioral context: invoke works on non-installed MCPs, returns connect/checkout links for auth/payment, retry semantics, install makes tool permanent, and writes require owner/admin. This is exactly the kind of disclosure beyond annotations that helps an agent.

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 a long single paragraph, but each sentence adds non-redundant information about core flow, alternatives, auth/payment handling, or permission requirements. It is dense but not bloated; a bulleted structure would improve scannability, but the length is justified by the tool's multi-action complexity.

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?

Despite no output schema and 23 parameters, the description covers the tool's overall functionality, edge cases (credential/payment links), permission requirements, and the prompt library subsystem. It lacks systematic parameter coverage but is otherwise complete for an agent to understand the tool's role and major behaviors.

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?

Schema description coverage is 0%, so the description must carry parameter meaning. It explains key params (action, query, mcp_id, tool_id, arguments, prompt_*), but many of the 23 params (limit, immediate, tier_slug, cancel_reason, etc.) are left unexplained. The description gives a strong high-level flow but doesn't sufficiently compensate for the lack of schema descriptions across all parameters.

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 defines the tool as the official mcp.ai marketplace and the way to run MCPs, covering catalog search, profiles, and execution. It distinguishes itself from sibling tools by detailing its unique capabilities (invoke, install, subscribe) and even references report_bug as a sub-command, reducing ambiguity.

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?

Provides explicit usage guidance: 'prefer invoke for a single/occasional use' and 'Use install only to make an MCP PERMANENT'. Also explains the core search→describe→invoke flow and mentions the prompt library alternative, giving clear when-to-use vs. alternative paths.

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