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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description adds useful context that it is pure computation with no cost. It also discloses the hex output encoding, but says nothing about determinism guarantees, accepted text encoding, or default algorithm 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 short sentences, zero filler, and the operation plus accepted algorithms are front-loaded before the 'pure computation, free' qualifier.

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?

With no output schema, the description usefully notes hex output, and the annotations cover the safety profile. The main omission is the default/optionality of the algorithm parameter, which matters for correct invocation of a 2-parameter tool.

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 coverage is 0%, so the description must carry the load and it partially does by listing the four accepted algorithm values. However, it never states whether 'algorithm' is optional or what the default is, and gives no constraints on 'text' (length, encoding), leaving real gaps.

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 ('Hash') and resource ('a text') and enumerates the supported algorithms, so the agent knows exactly what computation happens. It does not name the nearest sibling (bursia_hmac, the keyed variant), so a subtle ambiguity remains, but the purpose itself is unmistakable.

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?

'Pure computation, free' implies no key, no network, no side effects and hints at the distinction from an HMAC tool, but the alternative is never named and there is no explicit when-to-use/when-not statement. Usage is inferable rather than stated.

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