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

Despite annotations indicating non-read-only, open-world, and non-idempotent behavior, the description adds critical context: invoke runs uninstalled MCPs without bloating the toolkit, may return connect or checkout links, and writes require admin role. It also explains the side-effect-free nature of one-off invokes. No contradictions with 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 dense and packed with essential information, structured around a logical flow. It covers all major actions and edge cases without excessive fluff, though it is a single lengthy paragraph that could benefit from bullet points. Every sentence adds value, making it appropriately concise for the tool's complexity.

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?

The description covers the entire lifecycle: discovery, description, invocation, installation, billing, reporting, and prompt library. It addresses common pitfalls (credentials, wallet balance, permissions) and does not rely on an output schema. For an agent to select and invoke this tool correctly, the description provides sufficient context.

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 23 parameters and 0% schema coverage, the description compensates by explaining the action-driven workflow and key parameters such as action, tool_id, arguments, and prompt_vars. However, it doesn't detail every parameter (e.g., cancel_reason, request_details), so some parameters remain under-explained. The description adds meaningful conceptual semantics beyond the schema.

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 explicitly states the tool is 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It clearly identifies the core flow (search, describe, invoke) and distinguishes from sibling tools, which are domain-specific (e.g., librelink_*). The purpose is unambiguous and detailed.

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: 'Core flow: action=search discovers MCPs by intent → describe returns one MCP's full profile... → invoke RUNS that tool.' It also contrasts install vs invoke ('prefer invoke for a single/occasional use') and notes that 'Writes... require workspace owner/admin.' This gives clear direction on when to use the tool and its alternatives.

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