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

Beyond the annotations, the description discloses permission requirements ('Writes ... require workspace owner/admin'), the one-off execution behavior of invoke, the fact that invoke works even when the MCP is not installed, and the credential/payment link flows. 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 densely informative; every sentence adds meaningful guidance. It uses labels like 'KEY', 'Core flow', and 'Use install only' to create structure, though it could benefit from bullet points or short paragraphs for easier scanning.

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, 23 parameters, and no output schema, the description is remarkably complete: it covers the core workflow, installation vs one-off invocation, auth and payment edge cases, permissions, billing actions, and the separate prompt library subsystem. It explains expected return artifacts for describe, invoke, get_prompt, and publish_prompt.

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 well by explaining the meaning of the action enum, tool_id selection via describe, and prompt_slug/publish_prompt flow. However, several parameters like limit, immediate, tier_slug, conversation, prompt_targets, request_details, and cancel_reason receive no explanation, so it is not fully sufficient.

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 identifies the tool as the official mcp.ai marketplace covering both discovery and execution of MCPs/tools. It goes beyond a vague verb by explaining the core flow (search → describe → invoke) and distinguishes this router-style tool from its siblings by enumerating its many capabilities.

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 guidance on when to use each action: 'prefer invoke for a single/occasional use', 'Use install only to make an MCP PERMANENT', and describes the retry flow for connect/checkout links. It also explains when subscribe/cancel, request_mcp, and prompt-library actions are appropriate.

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