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

The description reveals key behaviors beyond the annotations: invoke runs tools even when not installed, writes require owner/admin, and credential/payment failures return connect/checkout links. This adds substantial context to the readOnlyHint=false and openWorldHint=true annotations without contradiction.

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 dense paragraph covering many facets without wasted words. It is front-loaded with the core purpose, but could be structured with bullets or sections for easier scanning; however, every sentence contributes value.

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 14 actions and 23 parameters, the description covers the main flows (search/describe/invoke, install/remove, prompt library) and important edge cases like auth and payment. It omits details on some actions (e.g., resume, report_bug) and return formats, but overall it is quite complete for such a complex tool.

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 must explain parameters. It explains high-level actions and flow, but does not map specific parameter names (e.g., mcp_id, tool_id, prompt_title) to each action. The names are intuitive but not explicitly documented for all 23 params, leaving gaps for an agent to infer.

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 is 'the official mcp.ai marketplace' that catalogs and runs MCPs. It uses specific verbs like search, describe, install, invoke, and explains the core flow, distinguishing it from sibling tools like authenticate or connect.

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?

Explicit guidelines are provided: 'prefer invoke for a single/occasional use', 'Use install only to make an MCP PERMANENT', and describes when subscription actions apply. It also explains how to handle capability requests like 'find an MCP that does X', and contrasts with list_tools for immediate callables.

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