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

Goes well beyond annotations by disclosing key behaviors: invoke works even when MCP is not installed, runs the tool 'pontualmente (one-off)' without adding to toolkit, returns connect/checkout links for auth/payment with retry instruction, and writes require workspace owner/admin. 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 appropriately structured: summary sentence, core flow with arrows, key invoke behavior, billing/permissions, prompt library. It's dense but every section adds value for a 14-action tool; it could be split into bullets for easier scanning but remains effective.

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 the tool's complexity (14 actions, 23 parameters), the description covers most critical behaviors: search/describe/invoke/install, billing, prompts, and permissions. However, it omits explanation of the 'resume' action and some parameters, and with no output schema it doesn't specify return structures (beyond the connect/checkout links), leaving minor gaps.

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, the description compensates by explaining the action enum semantics and several key parameters (mcp_id, tool_id, arguments, prompt_*). However, some parameters like 'immediate', 'tier_slug', 'conversation' are left unmentioned, though many are self-evident from their names.

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 the tool's role: 'The official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It distinguishes itself from siblings by covering a wide range of actions (search, describe, invoke, install, prompts) with a coherent core flow, whereas siblings like authenticate/connect are narrowly scoped.

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 usage guidance: 'prefer invoke for a single/occasional use' and 'Use install only to make an MCP PERMANENT'. It outlines a step-by-step flow (search → describe → invoke) and explains when to use other actions (list_tools, subscribe/cancel, report_bug, request_mcp, prompt actions). Also clarifies permission requirements for writes.

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