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

The description adds rich behavioral context beyond annotations: invoke runs tools even when the MCP is not installed, returns connect or checkout links for auth/payment, and does not bloat the tool list. It also discloses that install/uninstall/subscribe/cancel require owner/admin and that published prompt links open without login. No contradiction with annotations exists.

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 and front-loaded with the core marketplace purpose, then covers workflows, permissioning, and the prompt library. It is a long single paragraph, but nearly every sentence earns its place given the tool's breadth; light formatting or separation would improve 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?

For a 23-parameter, multi-action tool with no output schema and sparse annotations, the description is quite complete: it explains the main lifecycle, one-off vs permanent execution, auth/payment flow, admin requirements, and prompt library. Missing details are mostly return-value shapes for search/list/describe and precise semantics for several billing and prompt parameters.

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 across 23 parameters, the description must compensate substantially. It explains core parameters like action, mcp_id, tool_id, query, and arguments through the workflow narrative, but many prompt_* fields, billing flags, and request/report parameters remain unexplained. It adds meaningful semantics but not enough to fully cover the schema gap.

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 establishes marketplace as mcp.ai's in-platform catalog and execution layer for MCPs/tools, with an explicit core search→describe→invoke flow. It is broad and multi-action rather than a single verb+resource, and it does not distinguish itself from the sibling report_bug tool (which shares the same name as one of its actions), so it falls just short of a 5.

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 gives explicit decision guidance: use invoke for occasional one-off runs, use install only when an MCP should be permanent, and prefer invoke over install when the tool is not installed. It also states when connect/checkout links appear and when workspace owner/admin is required, making when-to-use very clear.

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