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

The description discloses key behavioral traits not in the annotations: one-off execution of invoke without installing, requirement for owner/admin on writes, and return of connect/top-up links. It also explains that search/describe flag installation status. These details complement the annotations (readOnlyHint=false, openWorldHint=true) and provide a rich behavioral picture. No contradiction with annotations.

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 long but information-dense, each sentence adds value. It is structured with a clear core flow and then lists actions in a logical sequence. The front-loading of 'official mcp.ai marketplace' and 'THE way to run them' sets context immediately. It could be more concise, but the complexity justifies the length; it avoids redundancy and maintains focus.

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 23 parameters and 14 actions, the description covers the main flows thoroughly (search/describe/invoke/install, subscribe/cancel, and the prompt library). It explains the output of invoke (connect/top-up links) but does not detail outputs for other actions (e.g., list_tools format, describe structure). It also glosses over some params like cancel_reason and resume. Yet it provides sufficient context for an agent to select and use the tool correctly in most scenarios.

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 coverage, the description must compensate, and it does by explaining the meaning of key parameters through the action flow (e.g., action, mcp_id, tool_id, arguments) and conditionals like 'invoke returns a connect link'. It covers the prompt-related parameters contextually (prompt_vars, prompt_targets) but does not enumerate every parameter explicitly. Given the complexity, this is adequate but not exhaustive.

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 it is the official MCP marketplace and catalog of tools, with a specific verb+resource: 'the in-platform catalog of every MCP/tool, AND the way to run them.' It explains the core flow (search → describe → invoke) and distinguishes itself from sibling tools like authenticate and connect by focusing on marketplace operations. It also covers the prompt library aspect, making its purpose comprehensive and unambiguous.

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 when-to-use guidance: 'prefer invoke for a single/occasional use' vs 'install only to make an MCP PERMANENT', and describes conditional behavior (connect link if credential needed, checkout if wallet empty). It also explains the core flow and specific actions (search_prompts, get_prompt, publish_prompt), giving clear context on when each action is appropriate. No exclusions are stated, but the guidance is highly actionable.

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