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

Beyond the annotations, the description discloses important behavioral traits: invoke works for non-installed MCPs via a one-off mechanism, credential needs surface as connect links, payment needs surface as checkout links, install makes tools permanently available, and write actions require workspace owner/admin. It also clarifies the prompt library is separate from MCP discovery. No contradiction with annotations exists.

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 but well-structured: opening definition, core flow with arrows, a KEY callout for the critical invoke behavior, then grouped mentions of install, list_tools, billing, writes, and the prompt library. Every sentence adds information, though the single-paragraph layout and the Portuguese word 'pontualmente' make it slightly harder to scan than an equivalent bulleted structure.

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, no output schema, and minimal annotations, the description covers a remarkable amount: the full workflow, permission model, billing/credential redirects, installed-state flags, and the prompt library. It is less complete on per-action return shapes/results and some parameter specifics, but for a gateway-style tool it provides enough context to select actions and invoke them correctly.

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 across 23 parameters, the description carries heavy explanatory weight and does add real semantics to the action enum by walking through search, describe, invoke, install, list_tools, subscribe/cancel, report_bug, request_mcp, and the prompt-library actions. It also clarifies the role of mcp_id/tool_id in the flow and prompt variables/slug for prompts, though many smaller params (tier_slug, immediate, conversation, etc.) remain explained only by name or not at all.

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 immediately identifies the resource ('the official mcp.ai marketplace') and states its dual role as catalog and execution layer. It lays out a concrete core flow (search → describe → invoke) and adds specific capability examples, making the tool's purpose unmistakable and clearly distinct from generic helpers.

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 one-off use, use install only for permanent toolkit additions, list_tools for currently callable tools, subscribe/cancel for billing, and request_mcp when nothing fits. It also explains when invoke will return connect/checkout links and that writes require owner/admin, which is strong alternative-selection guidance.

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