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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the safety burden is lifted. The description adds genuine context beyond that: it enumerates the returned content (script URL, scan, hashes, metrics, ML vector) and discloses that functions and HTTP headers are opt-in rather than default.

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 sentence with the lookup key front-loaded, then the return payload, then the opt-in flags. No filler, no repetition of the title.

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 no further explanation, and the description still summarizes them helpfully. Annotations cover the safety profile. The only omission is behavior on a nonexistent id, which is minor for a read-by-id tool.

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 must carry the load, and it largely does: it identifies fingerprint_id as numeric and explains that include_functions and include_http_headers 'add more detail'. It stops short of stating the null/false default behavior explicitly, so it is not fully compensating.

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?

States a specific verb (get), a specific resource (one JavaScript fingerprint record), and the lookup key (numeric fingerprint_id). This distinguishes it from get_js_fingerprints (list) and the many search_js_fingerprint_* siblings without requiring schema inspection.

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?

Usage is implied by 'by its numeric fingerprint_id' — the agent knows it needs an id in hand. However, it names no alternatives or exclusions (e.g., get_jsfingerprint_source, get_jsfingerprint_similar, get_jsfingerprint_bundle_stats) that an agent might otherwise confuse for detail retrieval on the same fingerprint.

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