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

The annotations already cover the safety profile (readOnly, idempotent, non-destructive, not open-world), so the bar is lower. The description still adds genuinely non-annotated context: the tool is free and it also discloses the limits of the checks themselves, which is useful for calibrating trust in the sibling verdict tools.

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 compact fragment with the cost qualifier front-loaded and the covered topics enumerated in descending order of usefulness. It is slightly clipped (no main verb, list-like), but nothing in it 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 zero-parameter, no-output-schema documentation tool, the description covers enough to know what the response will teach. The one gap is that it does not say whether the answer is general reference material or must be paired with a specific verdict from another call, which an agent may need to know before invoking it.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. If anything the wording 'each field of a verdict' could briefly suggest a verdict input exists, but the empty schema resolves that immediately.

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 names a specific verb+resource (explain verdict fields) and enumerates the exact topics covered: SAFE/CAUTION/DANGER meanings, score, per-field meaning, check limits, prices, JSON schema. It reads clearly as reference documentation, distinct from the check/get siblings, though it never explicitly contrasts itself with 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?

'Free.' is a soft usage cue implying this is the no-cost option when you only need to interpret an existing verdict rather than run a check. However, it never states when to call this versus check_base_token or get_sample_verdict, leaving that routing to inference from the tool name.

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