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

The description reveals key behavioral traits beyond annotations: invoke works even when the MCP is not installed, returns a connect link if credentials are needed, and returns a checkout/top-up link if the wallet is empty. It also states that writes require workspace owner/admin, and that search/describe flag installation status. These are concrete, non-obvious behaviors not present in the 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 a dense, single paragraph with long sentences and many clauses, making it harder to parse. It front-loads with the core purpose and then covers many details, but the structure could benefit from bullets or shorter sentences. Every sentence earns its place, but the formatting hampers quick comprehension.

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 with 23 parameters and no output schema, the description covers the main flows, auth requirements, and the prompt library well. It omits details on some actions (e.g., resume, detailed behavior of report_bug/request_mcp) and specifics on return values, but it is largely complete for selecting and using the tool at a high level.

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?

Schema description coverage is 0%, so the description must compensate. It does explain the action enum thoroughly and implicitly references query, mcp_id, tool_id, and arguments through the workflow. However, many parameters (limit, immediate, tier_slug, prompt_body, prompt_vars, cancel_reason, etc.) are not explicitly described, leaving unclear how to populate them.

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 identifies the tool as the mcp.ai marketplace catalog and execution interface, with a specific verb+resource structure: 'search discovers MCPs', 'describe returns one MCP's full profile', 'invoke RUNS that tool'. It also distinguishes from sibling tools by focusing on marketplace functionality rather than authentication, connection, or version reporting.

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 decisions: 'prefer invoke for a single/occasional use' vs 'Use install only to make an MCP PERMANENT', and outlines the core flow of search → describe → invoke. It also clarifies when to use list_tools, subscribe/cancel, report_bug, request_mcp, and the prompt-library actions, with sufficient context to guide selection among the many actions.

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