crypto.hash

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

Annotations already cover safety (readOnly, idempotent, closed-world), and the description adds genuinely new behavior: the encoding applied to input, the exact hex casing of output, the blake2b 64-byte output length, and the security limitation of unsalted/uniterated hashing. It does not state error behavior for unsupported algorithm values, which keeps it from a 5.

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?

Three sentences, front-loaded with output format, then algorithm options, then the usage caveat. No filler or restatement of the tool name.

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 details need not be restated, and the description nevertheless pins down the hex format. Only edge cases (e.g., unsupported algorithm names, empty input) are 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 must carry the parameter burden, and it does: algorithm's allowed values, its default (sha256), its case-insensitivity, and the differing output size for blake2b. The data parameter gets only an implied meaning (string, UTF-8 encoded) rather than an explicit statement.

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 UTF-8 string) plus the exact output form (lowercase hex). It is trivially distinguishable from the neighboring crypto tools, which are number-theoretic (gcd, modinv, modpow) or certificate-related (crypto.crt).

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?

Explicitly frames the tool as an integrity-fingerprint function and explicitly excludes password storage ("솔트와 반복이 없어 비밀번호 저장에는 쓰지 않는다"), which is strong when/when-not guidance. It does not name an alternative to use for password hashing, but no sibling offers one, so the gap is minor.

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