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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so safety and repeatability are covered. The description adds one genuinely useful behavioral signal beyond that: 'Source can be long', warning the agent about potentially large payloads. It adds nothing further about auth, rate limits, or truncation behavior.

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?

Two tight sentences, front-loaded with the action and key parameter, followed by a short, useful caveat about output size. No filler or redundancy.

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 the description need not enumerate return values, and the safety profile is fully covered by annotations. For a single-parameter read tool it is nearly complete; the only gap is guidance on obtaining a valid fingerprint_id and how to handle the 'long source' case (e.g., truncation or paging).

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 burden for the single parameter. It clarifies that fingerprint_id is the numeric identifier of the JavaScript file and that retrieval is by that id, which is slightly more than the bare 'Fingerprint Id' title in the schema, but it does not explain valid ranges, how ids are sourced, or error behavior for unknown ids.

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 and resource: retrieve the stored source code of one JavaScript file, keyed by fingerprint_id, and previews the returned fields (SHA-256, URL, length). It is clearly distinguishable from list/search tools in the get_jsfingerprint_* family. It does not explicitly contrast itself with the sibling get_jsfingerprint, which likely returns metadata rather than source, so it falls short of full sibling differentiation.

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 description implies the caller must already hold a fingerprint_id but never says when to prefer this tool over get_jsfingerprint, get_jsfingerprint_similar, or the many search_js_fingerprint_* tools, nor how to obtain a valid id. No when-to-use or when-not conditions are given.

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