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

Goes well beyond annotations by revealing that invoke can run uninstalled MCPs without adding to the toolkit, returns connect/checkout links for auth/payment, flags installed status in search/describe, and notes that writes require workspace owner/admin. No contradiction with annotations (readOnlyHint=false, openWorldHint=true).

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 dense but efficient—every sentence adds value. However, it is a long wall of text that mixes multiple topics (MCP discoverability, invoke semantics, billing, admin requirements, prompt library) without clear breaks, making it harder to parse than necessary.

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 14-action tool with no output schema, the description is quite complete: it covers core flows, invoke vs install, credential/payment handling, admin permissions, and the prompt library. Yet some actions (resume) and many parameters are left unexplained, and return formats are only partially described.

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 and 23 params, the description must compensate. It thoroughly explains the action enum values, but most parameters (mcp_id, arguments, limit, cancel_reason, etc.) remain undocumented. It adds meaning to the core flow but not enough to fully map parameters to actions.

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—the catalog for MCPs/tools and the execution engine. It outlines a specific flow (search → describe → invoke) and distinguishes the prompt library as a separate feature, making it distinct from siblings.

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 one-off tasks, install for permanent additions; subscribe/cancel for billing, request_mcp for new MCPs, search_prompts for prompt text. It also explains follow-up behavior (connect/checkout links) and admin requirements for writes, offering clear alternatives.

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