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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds meaningful behavioral context beyond these: it specifies the scan scope (what it checks), the output form (paths and remediation), and the key guarantee of never exposing source contents. This reassures an agent about safety and output boundaries.

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?

Two sentences, no filler. The first sentence front-loads the purpose and scope; the second clarifies outputs and a critical safety constraint. Every word adds value.

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 what the tool scans, what it returns, what it never returns, and its public-repo requirement. An output schema exists for return values, so no further explanation of the response shape is needed. Complete for an agent to call this correctly.

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% for the single parameter repository_url, with a clear format and description. The tool description does not add extra semantic detail about the parameter (e.g., URL validation rules or expected format), but the schema already covers it adequately. Baseline 3 is appropriate.

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 ('scan'), a specific resource ('one public GitHub repository'), and enumerates the exact categories checked (x402 implementation, HTTP 402 tests, payment configuration, buyer documentation, discovery metadata, CI gates, sensitive filenames). It also clarifies what it returns (paths and remediation) and what it never returns (source contents). This distinguishes it from sibling audit/verification tools, which likely target broader or different scopes.

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 a pre-deployment use case but does not explicitly contrast this tool with the sibling tools like ontario_x402-implementation-audit or x402_readiness_verify. An agent would need to infer when to pick this over those. No exclusions or alternative-routing guidance is provided.

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