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

Discloses important behavioral details beyond the annotations: invoke runs tools one-off without installing, returns connect or checkout/top-up links on credential/payment failures, and requires workspace owner/admin for writes. Also explains the installed_in_toolkit vs installed_in_workspace flags, giving a realistic picture of side effects and prerequisites. No contradiction with readOnlyHint=false; the description openly acknowledges that install/uninstall/subscribe/cancel are mutations.

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 dense; the length is warranted given the tool's 14 actions and 23 parameters. It front-loads the core flow and then covers auxiliary actions and the prompt library. Though a bulleted structure would improve scannability, each sentence contributes unique value without filler.

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 of this complexity with no output schema, the description is exceptionally complete: it covers search/describe/install/invoke, billing actions, bug reports, MCP requests, and the prompt library. Minor gaps include the 'resume' action and some parameters like tier_slug/immediate, but the core decision paths an agent needs are fully articulated.

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?

Since the schema has 0% coverage, the description compensates meaningfully by explaining the core parameters (action, mcp_id, tool_id, arguments) and the prompt_* fields. It maps actions to parameter usage in the flow. However, it does not explain every parameter, such as limit, immediate, tier_slug, or resume-related fields, leaving some parameters under-documented for full self-service use.

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 explicitly states the tool is 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them,' using specific actions (search, describe, invoke, install) and covering both MCP discovery and execution. It clearly differentiates from siblings by defining its role as the central catalog/runtime, while siblings like authenticate, connect, and report_bug are narrowly scoped utilities.

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?

Offers explicit guidance on when to use invoke (one-off, works even for uninstalled MCPs) versus install (permanent toolkit addition), and names alternatives like request_mcp for missing capabilities. It also identifies list_tools for currently callable tools and distinguishes the prompt library as separate from MCP tools, providing a clearly mapped decision flow.

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