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

Annotations already declare the operation read-only, idempotent, and non-destructive. The description adds meaningful behavioral context beyond those: results are ranked best guesses rather than proof, because a hash does not carry its algorithm. It also names the covered algorithm families and a source, which helps set expectations about scope and reliability.

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 efficient and front-loaded with the core purpose. The algorithm list is long but useful for scope-setting. The source URL is slightly extraneous but does not bloat the description enough to hurt clarity.

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 a single parameter, strong annotations, and an existing output schema, the description is complete. It explains the input, the heuristics used, the algorithms covered, and the probabilistic nature of the result. Nothing essential for correct invocation is missing.

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 already documents the single `hash` parameter with 100% coverage. The description adds little beyond restating that the tool inspects the hash string, though the mention of length, character set, and prefix gives some sense of what the tool considers. This meets the baseline for high schema coverage but does not go beyond it.

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 identifies the most likely algorithms behind a hash string using length, character set, and prefix, which is a specific verb and resource. It is not tautological and the algorithm list adds concreteness. However, it does not explicitly differentiate itself from siblings like hopi_hash_generator or hopi_cipher_identifier, leaving that distinction to the agent.

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 when you have a hash string and want to know which algorithm produced it. It gives useful heuristics about what the tool inspects, but it does not state when to use this tool instead of alternatives, nor does it mention exclusions such as passwords needing hashing or ciphertext identification.

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