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

With zero annotations, the description carries the full burden, and it does add real behavioral context: it names the underlying implementation (node crypto), the supported algorithms, and the output encodings, plus '纯内置' indicating no external dependency. It still omits determinism/idempotency, error behavior, and input-size constraints.

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?

A single dense line that front-loads the resource and then the supported algorithms/encodings; no filler. Slightly compressed to the point of omitting needed detail, but structurally sound.

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 4-parameter tool with 0% schema coverage, no annotations and no output schema, the description covers algorithms and output format adequately but leaves the two input-data parameters ambiguous and adds no usage routing. Functionally adequate but with clear gaps.

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% and no enums exist, so the description must compensate. It usefully pins the legal values for algorithm (sha256/sha1/md5/sha512/ripemd160) and encoding (hex/base64), but leaves the data-vs-text parameter pair completely unexplained, which is the more confusing part of the schema given zero required fields.

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 and resource (哈希生成 / hash generation) and enumerates the supported algorithms and output encodings, so the agent knows exactly what the tool computes. However, it never distinguishes itself from the near-identical siblings x402-hash and x402-hash-file, which is the main source of selection ambiguity.

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?

There is no statement of when to use this tool versus x402-hash, x402-hash-file or a keyed-hash sibling. The algorithm list implies a use case but provides no routing guidance or exclusions.

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