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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered and the description does not contradict it. The description adds genuinely useful non-annotation behavior: the $0.02 USDC per call x402 cost, which materially affects invocation decisions. It stops short of explaining payment/wallet prerequisites or latency.

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, front-loaded with the tool's identity and scoring behavior, followed by the use case and cost. No filler, no repetition of the schema, and the pricing constraint is placed where an agent will see it.

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?

With no output schema, the description correctly carries the return-value burden, describing the 0-10 score, the error/unsupported-claim list with fixes, and the improved answer. It omits how missing optional inputs (question/rubric) are handled and the response structure, but is otherwise sufficient for correct invocation.

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 only 25% (only 'sources' is documented as pipe-separated URLs), so the description must compensate. It names the semantic role of each input (answer, question, rubric, source URLs) but adds no format, precedence, or optionality detail beyond that, leaving gaps the schema does not fill.

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 ('Answer grader: scores a draft answer 0-10') and enumerates both inputs (question, rubric, source URLs) and outputs (errors, unsupported claims, improved answer). It is far more specific than a tautology, but it never names or routes against obvious siblings such as answer, ask, second_opinion, or citecheck, so an agent gets no explicit differentiation guidance.

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?

One phrase, 'A self-check before an agent ships,' implies the usage context, but there are no explicit when-to-use/when-not conditions and no alternatives are named despite many adjacent answer/verification tools in the sibling list. The guidance is present but inferential rather than actionable.

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