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

With no annotations, the description must carry the behavioural load, and it does add real context: cost of €0.0005 per call, the requirement for an API key in the Authorization bearer header, and the shape of the returned digests. It still omits anything about side effects, failure modes for invalid algos, or output size for multi-algorithm requests, so the disclosure is partial rather than rich.

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?

Purpose, cost and auth are front-loaded in the first two sentences, then parameters are compactly listed. No sentence is filler and the dense format is appropriate for a small utility tool.

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 not be re-explained, and the description covers the commercial and auth context an agent needs before calling. It is close to complete; only edge-case behaviour (invalid algo, missing text) is unaddressed.

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 is the only source of parameter meaning, and it enumerates all four: text (plain or base64), encoding (utf8 default | base64), algo (md5/sha1/sha256/sha512/comma-list/all) and key (optional HMAC). This goes well beyond the bare schema, though it leaves e.g. what a comma-list means for output formatting and key encoding unstated.

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 names the concrete operation (computing md5/sha1/sha256/sha512 digests) and its output forms (hex and base64), plus HMAC keying. It does not explicitly contrast itself with near neighbours such as base64 or jwt_tools, but the verb+resource is specific enough to select it unambiguously.

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 rather than stated: the tool computes digests of text or base64-decoded bytes, and the note 'plain or base64, see encoding' hints at when the encoding switch matters. There is no explicit when-to-use/when-not guidance or naming of an alternative tool for checksums.

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