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

Adds significant behavioral context beyond the annotations (which only indicate non-read-only, non-destructive, open-world). Details like invoke working even when the MCP is not installed, returning connect/checkout links requiring user action then retry, requiring workspace owner/admin for writes, and the one-off install behind invoke are all disclosed, giving the agent a full picture of side effects and preconditions.

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 single paragraph but uses signposts like 'Core flow:', 'KEY:', and 'Use install only' to organize the content. It is long, but every sentence adds necessary context for a tool with 14 actions and 23 parameters; could be improved with bullet points but is appropriately sized for the complexity.

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 absence of an output schema and the tool's complexity, the description is remarkably complete: it covers the search/describe/invoke workflow, install vs invoke semantics, auth/payment edge cases, prompt library, permissions, and billing actions. No obvious gaps remain for an agent to select and invoke the tool correctly.

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 values (search, describe, install, invoke, list_tools, subscribe/cancel, report_bug, request_mcp, prompt actions) and key parameters like mcp_id, tool_id, arguments, and prompt_* fields. It does not describe all 23 parameters (e.g., limit, immediate, tier_slug, cancel_reason), but the most semantically important ones are covered.

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 purpose as 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It then explains the core action flow (search → describe → invoke), distinguishing it from sibling tools like the feegow_* set, which are domain-specific operations.

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 when-to-use guidance: 'prefer invoke for a single/occasional use; use install only to make an MCP PERMANENT in the active toolkit,' and names alternatives like list_tools for currently callable tools and request_mcp when nothing fits. Also states permission requirements for writes, making it clear when the tool can be used.

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