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

Annotations declare read-only, idempotent, non-destructive, so the safety profile is covered. The description adds real value beyond that: the licensing requirement for non-default lookups and the auth header (x-crawlcheck-key), plus the Merkle-proof/signed-manifest guarantee, which no annotation conveys.

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?

Dense but front-loaded: the first clause states the purpose, then the returned evidence, then how to call it. It's long but nearly every clause carries functional information; acceptable for a complex explain tool.

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 read-only explanation tool with no output schema, the description covers what evidence comes back, which id forms are accepted, the domain shortcut, and the auth requirement for restricted lookups. The only gap is the unexplained path parameter and the exact return shape, which is minor.

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 coverage is 75%; the description clarifies the id semantics (d1: decision vs f1: finding vs report id) and the domain-alone behavior ('top finding'), and ties the code parameter to its licence restriction. path is left unexplained, but most parameters gain meaning beyond the bare schema strings.

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+resource (explains why a finding was decided) and enumerates exactly what is returned — the rule and revision, the fetches compared with identity/status/bytes/sha256, condition timing, and a Merkle proof. This is far more specific than any sibling and makes the tool unmistakable.

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?

It gives clear input-driven routing: give an id (d1: or f1:) or a domain for its top finding. It also flags a licence prerequisite for looking up other findings or by code. It doesn't name an alternative sibling, but the when-to-use conditions are explicit.

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