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

Annotations already indicate readOnlyHint=false, openWorldHint=true, and destructiveHint=false. The description adds substantial behavioral context beyond those flags: writes require workspace owner/admin, invoke returns a connect link when credentials are missing, paid tools return a checkout/top-up link when the wallet is empty, and one-off invoke does not install or bloat the tool list. 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 front-loaded with the core flow before alternative actions, and every sentence conveys useful information. It is, however, a dense single paragraph that mixes catalog navigation, billing, permissions, and prompt-library behavior, with one stray Portuguese word ('pontualmente'). It would be more scannable with bullets, but it is not wastefully verbose.

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, no output schema, and complex business logic, the description covers the main workflows, auth/payment edge cases, permission requirements, and prompt-library operations. It is not fully complete—return-value shapes, search pagination, and error behavior are absent, and many parameters remain unexplained—but it provides enough context to use the primary path effectively.

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% with 23 parameters, so the description must compensate. It explains the role of action values and explicitly mentions tool_id, mcp_id, and prompt variables/slugs. However, many parameters (limit, immediate, tier_slug, conversation, prompt_tool, prompt_targets, prompt_category, request_details, arguments, etc.) are not explained, leaving the agent to infer their meaning from names alone.

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 official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them'. It specifies the core verbs (search, describe, invoke, install) and explicitly mentions report_bug as an action, which distinguishes it from the sibling tool of the same name. The purpose is unambiguous despite the broad scope.

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 with named alternatives: 'Use install only to make an MCP PERMANENT... prefer invoke for a single/occasional use', and explains when to use search/describe, list_tools, subscribe/cancel, request_mcp, and the prompt-library actions. It even includes concrete triggering examples like 'find an MCP that does X' and 'consulta um CPF'.

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