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

With no annotations, the description partially discloses behavior by listing algorithms and output encoding, but omits details like deterministic nature, potential errors (e.g., invalid algorithm), or security considerations (e.g., secret handling). It adds moderate context beyond the schema.

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?

The description is a single concise sentence that front-loads purpose and key details. While efficient, it could be slightly expanded to cover parameter semantics without becoming verbose.

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?

For a simple cryptographic tool with no output schema or annotations, the description covers essential aspects (algorithm, output format) but lacks detail on error handling, default behavior, and return format, making it adequate but not comprehensive.

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 compensate. It explains 'algorithm' and 'encoding' via the listed options but does not clarify 'secret' (the key) or 'message' (the data) beyond their names, leaving half the parameters underdocumented.

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 tool performs HMAC signing on a message, specifies supported algorithms (sha1/sha256/sha512) and output formats (hex/base64), distinguishing it from sibling tools like hmac_verify (verification) and hash functions (no secret).

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 provides no guidance on when to use this tool versus alternatives such as hmac_verify, jwt_sign, or simple hashing. It lacks explicit conditions, exclusions, or references to sibling tools.

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