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

Beyond the annotations, it discloses important behaviors: invoke runs tools one-off without installing, returns connect links for credentials and checkout links for payment, writes require workspace owner/admin, and prompt library links open without login. This is rich behavioral context that helps the agent predict side effects and prerequisites.

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 information-rich, front-loading the core flow and then covering edge cases and the prompt library. It contains no wasted words, but the long single-paragraph structure could be improved with bullet points for scanability. Overall, it earns its length.

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 tool of this complexity (23 params, no output schema, many actions), the description covers nearly all necessary context: core workflow, auth requirements, payment edge cases, permission levels, and the separate prompt library. It leaves minimal gaps for an agent to safely select and invoke the right action.

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, the description carries the burden. It explains the semantics of the 'action' parameter thoroughly and implies the roles of other parameters (query, limit, mcp_id, tool_id, arguments, prompt_* fields) through the workflow. However, many of the 23 parameters are not individually documented, so the agent must rely on names and defaults for some fields.

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 that the marketplace is 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It enumerates the core actions (search, describe, invoke, install, etc.) and distinguishes itself from siblings by describing its own role as a catalog and runtime.

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 when-to-use guidance: 'prefer invoke for a single/occasional use' and 'Use install only to make an MCP PERMANENT'. It outlines a core flow (search→describe→invoke) and explains when to use list_tools, subscribe/cancel, report_bug, request_mcp, and the prompt library actions, plus auth/payment retry steps.

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