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

While annotations are minimal (readOnlyHint=false, openWorldHint=true, etc.), the description adds substantial behavioral context: invoke runs tools one-off without installing, returns connect/checkout links for auth/payment, requires retry after user acts, and clarifies that install/uninstall/subscribe/cancel are writes requiring owner/admin. This goes well beyond annotation hints and covers auth, payment, and side effects.

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 contains highly valuable information but is a dense, unstructured paragraph with many run-on clauses. It front-loads the core purpose and flow, but the sheer volume of actions and prompt-library details would benefit from bullet points or clearer separation. Every sentence adds substance, but the presentation hurts scannability.

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 (14 action values, no output schema, minimal annotations), the description is remarkably complete: it covers discovery, execution, installation permanence, auth/payment link flows, permission requirements, installed-status flags, and the prompt library. It lacks explicit return-format details and error/retry nuance, but for a hub tool it provides enough context to act.

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 23 parameters and 0% schema description coverage, the description must compensate, and it does explain the central action parameter and flow (search, describe, invoke, install, subscribe, cancel, list_tools, prompt actions). However, many remaining params (limit, query, immediate, tier_slug, cancel_reason, prompt_targets, etc.) are not explicitly mapped to their meanings, leaving gaps for a tool this broad.

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 catalog of every MCP/tool and the way to run them. It explicitly distinguishes the core flow (search → describe → invoke) and differentiates from sibling tools by positioning itself as the meta-level discovery/execution hub.

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 gives explicit when-to-use guidance: 'prefer invoke for a single/occasional use' vs 'Use install only to make an MCP PERMANENT', and notes that list_tools lists what is callable right now. It also provides alternatives and exclusions, such as using request_mcp when nothing fits, and flags workspace owner/admin requirements for writes.

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