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

The description goes well beyond the sparse annotations by explaining side effects: invoke can return auth or checkout links when credentials/payment are needed, writes require workspace owner/admin, and invoke does a one-off install without bloat. It also clarifies installed_in_toolkit vs installed_in_workspace flags and the prompt library's shareable-link behavior.

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 single informational paragraph with no wasted sentences, but its length and rapid-fire clauses make it harder to scan. For a 23-parameter automated marketplace tool with 14 actions, the density is understandable, though a bullet list or sectioned split would improve clarity.

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 size and no output schema, it covers nearly every action: search, describe, invoke, install, subscribe/cancel, report_bug, request_mcp, and the prompt library. There are still gaps (e.g., 'resume' action is not explained, and parameter-specific examples are missing), but for such a broad surface the description is unusually complete.

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 carries a heavy burden. It adds meaning to the most important parameters (action, query, mcp_id, tool_id, arguments, prompt_*, tier_slug implied by billing) and lays out the call sequence. It does not describe all 23 params or give concrete formats, so it is a solid but not exhaustive compensation.

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 opens with 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them' and then walks through the search → describe → invoke flow. This makes the tool's full scope explicit and differentiates it from the sibling authentication, connection, and informational tools.

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?

It gives concrete when-to-use guidance: 'Use search if you need to find an MCP by intent', 'Use invoke when you need a one-off run without installing', and 'Use install only to make an MCP permanent'. It also names alternatives like list_tools for 'what is callable right now' and request_mcp when nothing fits.

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