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

Discloses that invoke runs uninstalled MCPs one-off, returns connect/checkout links when credentials or payment are missing, and requires workspace owner/admin for writes. These behaviors go well beyond the annotations, which only give false hints for readOnly and destructive.

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?

It is a single dense paragraph that front-loads the main purpose and then covers many actions. Every sentence adds value, but the structure could be improved with lists or clearer separation between the MCP marketplace and prompt library sections.

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 large number of actions and 23 parameters, the description covers key behaviors comprehensively: billing, auth, admin permissions, one-off vs permanent execution, and prompt library operations. However, it omits specifics on parameters like resume, cancel_reason, prompt_vars, and does not describe return values, leaving some gaps.

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?

The description explains the action parameter and key values (search, describe, invoke, install, etc.) and how tool_id/arguments are used, but does not detail the other 21 parameters like limit, query, message, or the many prompt_* fields. With 0% schema description coverage, it only partially compensates for the undocumented 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 states the tool is the official mcp.ai marketplace catalog and the way to run MCPs/tools, with a search → describe → invoke core flow. It also encompasses the prompt library, distinguishing it from sibling tools like authenticate, connect, or report_bug.

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?

Explicitly advises using invoke for one-off usage and install for permanent additions, and explains when to use list_tools, request_mcp, report_bug, and subscribe/cancel. It also notes auth/payment prerequisites and owner/admin requirements.

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