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

The description discloses many behaviors not in annotations: invoke works without install, returns connect/checkout links, requires auth for writes, and distinguishes installed_in_toolkit vs workspace. These significantly enrich the agent's understanding beyond the minimal 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?

While long, the description is logically structured: it opens with the tool's essence, then explains the search→describe→invoke flow, key behaviors, installation distinctions, and the separate prompt library. It is front-loaded and each section adds value, though it could be tightened for 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?

Given the tool's complexity (23 parameters, many actions), the description is remarkably complete: it covers discovery, execution, installation, auth, payment, writes, and the prompt library. It also hints at return values (e.g., 'describe returns full profile', 'invoke returns connect/checkout links'), making it sufficient for an agent to use correctly without an output schema.

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 must compensate. It explains key parameters like action, mcp_id, tool_id, arguments, and prompt-related fields through the core flows, but does not systematically define all 23 parameters (e.g., tier_slug, cancel_reason, prompt_targets). It covers enough to guide correct usage but leaves some ambiguity.

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 it is the official mcp.ai marketplace catalog and execution interface, with a specific verb 'search', 'describe', 'invoke', etc. It distinguishes from siblings by being the central hub for tool discovery and execution, while also covering the prompt library separately.

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?

It provides explicit guidance on when to use invoke vs install (e.g., 'prefer invoke for a single/occasional use' and 'use install only to make an MCP PERMANENT'), and mentions alternatives like report_bug and request_mcp. It also clarifies that writes require owner/admin, helping the agent decide when to act.

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