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

Discloses many behaviors beyond annotations: invoke works even when the MCP is not installed, returns a connect link for credential needs, returns a checkout/top-up link for paid MCPs, and requires retry after user action. It also clarifies that install is permanent while invoke is one-off, and that prompt library is about text prompts, not MCPs.

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 dense paragraph that mixes multiple domains: MCP discovery, execution flow, billing, admin rules, and prompt library. Every sentence adds value, but the lack of structure makes it hard to scan. Bullets or section breaks would improve readability.

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 23 parameters and no output schema, the description is remarkably complete: it covers the core flow, one-off invoke behavior, auth/top-up edge cases, admin requirements, and the prompt library. Gaps remain for actions like resume, the immediate parameter, and specific return shapes for some actions.

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?

Schema coverage is 0%, so the description carries the burden. It explains key parameters like action, query, mcp_id, tool_id, arguments through the search/describe/invoke flow, and prompt-related parameters via search_prompts/get_prompt/publish_prompt. However, some parameters (immediate, resume, conversation, cancel_reason) are not explicitly addressed.

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 — the catalog of every MCP/tool and the way to run them. It uses specific verbs and resources (search, describe, invoke, install) and distinguishes from sibling tools like authenticate/connect by focusing on discovery and execution.

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: core flow (search → describe → invoke), prefer invoke over install for one-off use, use install for permanent toolkit additions, list_tools to see what's callable, request_mcp when nothing fits. Also notes that writes require owner/admin.

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