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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds valuable 'deterministic' and 'stable' traits, indicating that the same public key always yields the same fingerprint and that the ID is consistent over time. However, it does not disclose potential errors or specifics like output format, so some gaps remain.

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 that is front-loaded with the action and purpose. Every word earns its place, and the parenthetical '(deterministic)' adds key behavioral context without bloat. This is an example of ideal conciseness.

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?

Given the tool's simplicity (one parameter, no output schema), the description covers the core purpose. However, it leaves out usage guidance, parameter details, and what exactly the return value looks like. While not excessively complex, the description is the only source of context and could be more comprehensive, especially to distinguish from identity-related siblings.

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?

The schema has 0% description coverage for the single parameter 'public_key'. The description only repeats that the fingerprint is derived 'from a public key', adding no extra meaning about format, encoding, length constraints, or any other semantics that would help the agent construct a correct input. The description fails to compensate for the lack of schema descriptions.

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 clearly states the verb 'derive' and the resource: a 'stable public fingerprint id' from a public key. The addition of 'deterministic' adds precision and distinguishes this from sibling tools like identity_create or identity_verify, which perform different operations.

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 tool is used to obtain a fingerprint from a public key, but it does not explicitly state when to use it versus alternatives or any exclusions. The sibling tools include identity_create and identity_verify, which could serve related purposes, so more explicit guidance would be helpful.

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