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

With no annotations, the description carries the full behavioral burden. It discloses the scoring model (weighted 0-100) and the rubric URL, which is useful, but says nothing about cost/payment requirements, whether the tool makes outbound network fetches, latency, failure behavior, or what the audit response contains.

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, front-loaded with the purpose, then the rubric name, the check list, the scoring scale, and the reference link. The parenthetical check list is long but genuinely informative; nothing is wasted.

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 two-parameter tool with no annotations and no output schema, the description should hint at the return shape (per-check results, score breakdown) and the payment gating. It partially covers scoring but leaves the response format and the payment flow for an agent to discover, which is a real gap.

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%, so both parameters are already documented (domain with an example, payment_signature as 'x402 payment signature once settled'). The description adds no meaning beyond the schema for either parameter, so the baseline of 3 applies.

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?

States a specific verb and resource ('Audits a domain's agent readiness') and enumerates the exact check categories (origin headers, robots.txt, llms.txt, sitemap, mcp.json, A2A card, x402 manifest, etc.), so the agent knows precisely what the tool evaluates. None of the siblings (btc_regime, echo_probe, resume_eval, x402_preflight) overlap, so no sibling disambiguation is needed.

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?

There is no explicit when-to-use or when-not-to-use guidance. Critically, the presence of the x402_preflight sibling and a payment_signature parameter implies a payment-gated flow, but the description never says whether to run x402_preflight first, how to obtain/settle the signature, or what happens if payment is missing.

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