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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds the meaningful behavioral trait that the hash is computed after whitespace/formatting removal, plus the prevalence aggregation it performs; it does not, however, disclose pagination, rate limits, or what happens when no match is found.

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 lookup action and folds the normalization explanation into a compact parenthetical. Nothing is wasted, though the trailing list of returned metrics is redundant given an output schema exists.

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?

An output schema exists and the annotations cover safety, so the return-value mention is not strictly required. The gaps that matter are the undocumented optional parameters (limit, date bounds, include_scans) and the failure to disambiguate from the plural sibling search_jsfingerprints_by_normalized_hash.

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 0%, so the description carries the full burden. It explains the required hash_value semantics well (normalized hash, not raw), but limit, from_date, to_date and include_scans are undocumented in both schema and description, so four of five parameters remain opaque.

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 (look up JavaScript by normalized hash) and even defines what 'normalized' means, which is genuinely clarifying. However, it does not distinguish this tool from the near-identical sibling search_jsfingerprints_by_normalized_hash, nor from the md5/sha1/sha256 hash-search family, leaving the agent to guess which hash variant to call.

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?

The parenthetical ('reformatted copies still match') implicitly tells the agent to reach for this over md5/sha256 when the script may have been reformatted, which is useful implied usage. But no alternative tool is named and no explicit when-to-use or when-not-to-use condition is given.

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