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

Annotations indicate only that the tool is not read-only and not idempotent. The description adds substantial behavioral context: writes require owner/admin, invoke runs one-off without installing or bloating the tool list, install makes permanent changes, and specific return behaviors for connect/checkout links. This goes far beyond 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?

Though long, the description is densely informative and every sentence earns its place. It is front-loaded with the tool's identity and core flow, then systematically covers exceptions, billing, permissions, and the prompt library. There is no redundancy or filler.

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 23 parameters and no output schema, the description comprehensively covers all primary actions, expected outcomes, prerequisites, and caveats. It explains the full lifecycle from discovery to invocation, installation, billing, and prompt publishing, making the tool's behavior predictable and actionable for an agent.

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 mapping actions to key parameters (action=search with query, describe with mcp_id, invoke with tool_id and arguments). It also covers prompt parameters like prompt_body and prompt_slug. However, not every parameter is individually explained (e.g., tier_slug, cancel_reason, prompt_targets), leaving some fields inferable only from context.

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 that this is the official mcp.ai marketplace, a catalog of MCP/tools and a way to run them. It enumerates distinct capabilities: search, describe, invoke, install, list_tools, subscribe/cancel, report_bug, request_mcp, and prompt operations. This distinguishes it from sibling tools, which are primarily focused on specific procfy financial 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?

The description provides an explicit core flow: action=search discovers MCPs, describe returns profiles, invoke runs the tool. It gives direct when-to-use guidance: 'Use install only to make an MCP PERMANENT' and 'prefer invoke for a single/occasional use'. It also explains what happens when credentials or payment are needed, detailing retry behavior.

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