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

The description goes well beyond the annotations by disclosing that writes require workspace owner/admin, that invoke can run an MCP without installing it, and that credential or payment gaps produce connection/checkout links. Since annotations already say the tool is not read-only, the extra behavioral details add clear value, although response shaping and pagination are not addressed.

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 packs a great deal of important information into one long, dense paragraph with little visual structure. It front-loads the main identifiebut but the sentence that mix core flow, exceptions, write permissions, billing, and prompt-library discussion together make it harder to parse than a bulleted or sectioned description would be.

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 very complex action-router with 14 actions and no output schema, the description is remarkably complete: it covers the core invoking flow, conditions around credentials and payments, distinguishing one-off vs permanent install, and maps the capability queries to search_prompts/get_prompt/publish_prompt. The main gap is that it does not explain the 'resume' action or the precise role of several optional params.

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 matters, and it does add high-level meaning by explaining the action values and the search/describe/invoke roles of mcp_id and tool_id. However, many parameters such as immediate, tier_slug, conversation, request_details, prompt_title, and prompt_description remain unexplained, so the description only partially compensates for the missing schema information.

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 opening sentence clearly identifies the tool as 'the official mcp.ai marketplace' and gives its dual role: catalog and execution layer. It then names the core flow of search, describe, and invoke, making the tool's purpose unmistakable and distinguishable from a generic listing or CRUD tool.

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: it says 'Use install only to make an MCP PERMANENT... prefer invoke for a single/occasional use' and distinguishes list_tools, subscribe/cancel, report_bug, request_mcp, and the prompt-library actions. This gives an agent clear decision logic for the task variants.

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