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

With no annotations, the description carries the full burden and does well: it discloses the paid model ('$0.01 USDC per call, paid with x402 on Base') and the shape of what comes back (score, subscores, top 5 fixes). It does not state that the operation is read-only/non-mutating or mention rate limits or failure behavior, so it falls short of a 5.

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?

A single dense sentence that front-loads the action and the coverage list; every clause (checks, score, fixes, price) carries information. It is a long run-on enumeration rather than cleanly broken structure, but nothing is padded.

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?

No output schema exists, and the description compensates by naming the key return fields (0-100 overall score, subscores, top 5 fixes) and the payment requirement. For a one-parameter read tool this is close to sufficient; only error/empty-result behavior and latency expectations are unaddressed.

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?

One parameter with 100% schema description coverage ('Domain, e.g. example.com'), so the schema already does the work and the baseline is 3. The description adds only the nuance that header checks run against https://<domain>, i.e. the scheme is assumed rather than supplied, which is a minor clarification.

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?

Opens with a specific verb+resource ('Full domain security audit') and enumerates exactly what is inspected: headers on https://<domain>, TLS, email, DNS records, RDAP, security.txt, robots.txt, plus a 0-100 score. The word 'Full' implicitly contrasts with the narrower siblings domainaudit_headers, domainaudit_tls and domainaudit_email, though the differentiation is never stated explicitly.

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?

Usage is only implied: an agent can infer this is the aggregate option versus the single-purpose domainaudit_* tools. There is no explicit 'use this when you want everything at once, use domainaudit_headers for just headers' routing, and no prerequisites or exclusions.

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