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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds value beyond that by specifying the threshold's valid range (0 to 1) and explaining the non-obvious semantics of exclude_same_scan (drops matches from the same scan), which an agent could not infer from the parameter name alone.

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?

Three compact sentences, front-loaded with the action and resource before the parameter notes, with no filler. Sentence two restates what the parameter name already implies, a minor redundancy, but overall the density is high.

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, so return values need not be described, and the description covers every input parameter plus the primary use case. What remains missing is disambiguation from the hash-based sibling and any statement about what 'similar' is measured on, which matters in a family of near-identical tools.

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 0%, so the description carries the full burden, and it does explain all five parameters: fingerprint_id as the anchor, threshold with its 0-1 range, limit/offset as pagination, and exclude_same_scan's effect. It omits the limit/offset defaults and any hint about score semantics, so it is strong but not exhaustive.

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 ('Find JavaScript files whose fingerprint is similar to the one with this fingerprint_id') plus the core scoping mechanism (threshold, pagination, same-scan exclusion), so the operation is unambiguous. It does not, however, distinguish itself from the very similarly named sibling find_js_fingerprint_similar_by_hash, leaving the agent to infer which entry point applies.

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?

'Useful for finding variants of one script' gives a concrete intent, which is more than nothing. But there is no when-not guidance and no pointer to the nearest alternative (find_js_fingerprint_similar_by_hash, search_js_runtime_similar), so the choice among near-duplicate siblings is left to inference.

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