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

No annotations are provided, so the description carries the full burden. It usefully discloses that the derivation is 'deterministic' and produces a 'stable' id, which is meaningful behavioral context for a pure function. However, it omits auth/permission requirements and any error 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?

A single front-loaded sentence with no padding; the output is stated before the input. The bracketed '[KEEP · internal]' marker is minor noise but does not obscure the meaning.

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?

No output schema exists, so the description must cover the return value; it names the 'fingerprint id' but does not describe its format. For a simple single-parameter deterministic tool this is adequate but leaves gaps.

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% and there is one parameter. The description implies the single input is a public key but adds no format, encoding, or length detail beyond what the parameter name already conveys.

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 (derive) and resource (stable public fingerprint id from a public key), which is clear enough to distinguish it from identity_create and identity_verify. It doesn't explicitly contrast with those siblings, but the deterministic derivation function is well defined.

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 says what the tool does but never states when to use it versus siblings like identity_create or identity_verify, nor any preconditions. No when/when-not guidance is present.

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