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

Annotations already indicate idempotency and non-destructiveness, but the description adds substantial behavioral context: the need to save credentials BEFORE calling, 'Identical retries only,' the fact that the response contains private reusable management credentials that must not be printed, and the explicit statement that it 'Does not charge money.' These details go well beyond the structured annotations and materially change how an agent should handle the call and result.

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 front-loaded: the core purpose appears in the first sentence, followed by concise operational warnings and clarifications. Every sentence earns its place, including the retry rule, credential-handling warning, and cost clarification. There is no filler or repetition of schema details.

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 complex 7-parameter mutating tool with no output schema, the description covers the most important operational concerns: prerequisites, retry behavior, side effects, and credential safety. It does not specify the exact response shape, but it explicitly warns that credentials are present in the response, which is the critical piece an agent needs. The remaining gaps are minor given the strong annotation coverage.

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 description coverage is 0%, so the description carries the burden of explaining parameters. It does so effectively for several critical fields: the 'supplied UUID' maps to idempotencyKey, the '32-byte secret' maps to submissionSecret, 'explicit user approval' maps to userApproved, and 'Save ... securely BEFORE calling' maps to credentialsSavedSecurely. The remaining parameters (destination, category, rulesVersion) are left to their self-explanatory names, which is a minor gap.

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 states a specific verb and resource: 'Creates ONE real public free listing after explicit user approval.' This clearly distinguishes it from the sibling tools capabilities and quote, which serve unrelated purposes. The emphasis on 'ONE real public free listing' removes ambiguity about scope and side effects.

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 gives clear context for when to invoke the tool: only after explicit user approval, and only after securely saving the UUID and secret. It also clarifies retry semantics with 'Identical retries only.' It does not explicitly name excluded scenarios or alternative tools, but the sibling distinction is obvious from the sibling names.

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