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

The description goes well beyond the sparse annotations (readOnlyHint=false, openWorldHint=true) by detailing side effects and special cases. It explains that invoke runs a tool one-off even if not installed, returns connect/checkout links for auth/payment, and requires workspace owner/admin for write operations. It also notes how search/describe flag installed states and how the prompt library behaves. These are important behavioral traits not visible in the 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 a single, dense paragraph that front-loads the purpose well but then becomes a wall of text. While every sentence adds information, the lack of structure (bullet points, short sections) makes it harder to parse. It is not appropriately concise for an AI agent to quickly extract key facts.

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 (14 actions, 23 params, no output schema, no param descriptions), the description covers the core flow and important edge cases (auth, payment, permanent vs one-off usage) but omits details for some actions (e.g., resume) and many parameters. It gives a solid high-level understanding but is not fully complete for all possible invocations.

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?

The schema has 23 parameters with zero descriptions (0% coverage), so the description carries the full burden of explaining them. It mentions a few key parameters (action, mcp_id, tool_id) and the idea of arguments for invoke, but it never explains most parameters such as limit, query, immediate, tier_slug, conversation, cancel_reason, prompt_*, etc. Without per-parameter detail, an agent will struggle to construct correct calls.

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 opens with a clear statement: 'The official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' This immediately establishes the tool's purpose and scope. It also outlines the core search→describe→invoke flow, distinguishing it from sibling tools like authenticate or connect, which are narrow and focused on specific actions.

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?

The description provides explicit when-to-use guidance, e.g., 'Use install only to make an MCP PERMANENT in the active toolkit... prefer invoke for a single/occasional use.' It also enumerates what each action (search, describe, invoke, list_tools, subscribe, report_bug, request_mcp, search_prompts, etc.) is for, and contrasts invoke vs install. This gives an agent clear decision rules for selecting the right action within the tool.

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