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

Annotations indicate read-only and open-world behavior, and the description adds meaningful context: the operation costs $0.05 USDC via x402 on Base or Solana, and it returns generated code. It also notes equivalence to a GET endpoint, which is useful extra behavioral detail 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?

The description is compact and front-loaded with the most important details: cost, action, and output. The parenthetical stack list and 'Same as GET /api/v1/fix' note are slightly redundant but not wasteful.

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 tool with no output schema, the description usefully explains the input (URL, stack, method), the cost, and the nature of the output (per-problem code fixes customized with payTo, amount, network, and route). It could be more explicit about error or edge-case behavior, but the core usage context is well covered.

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 100%, and the description largely restates the stack enum and defaults already present in the schema. It adds no significant new parameter-level meaning beyond what the input schema provides.

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 identifies the tool's purpose: it diagnoses an x402 endpoint and returns concrete code fixes per problem. The verb 'returns' and resource 'x402 endpoint' are specific, though it doesn't explicitly name sibling tools to differentiate them.

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 implies usage when a user needs a fix plan for an x402 endpoint, and mentions the cost and supported stacks. However, it provides no explicit guidance on when to choose x402_fix over x402_diagnose, x402_preflight, or x402_quick_check.

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