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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states 'input discarded' but does not explain what happens to the input, what the output is, whether the tool has side effects, or what 'CityHash hex length' means in practice. The description is too terse to disclose meaningful behavioral traits beyond the vague notion that inputs are not retained.

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 extremely short, which is concise, but it is under-specified rather than efficiently informative. It front-loads the name-like phrase 'CityHash hex length' but does not earn its place by explaining the tool's behavior. A single cryptic phrase is not sufficient for a tool with 9 parameters and no annotations.

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 the tool has 9 optional parameters, no output schema, and no annotations, the description is far from complete. It does not explain what the tool returns, how to interpret the parameters, or what 'input discarded' means for the caller. The complexity of the schema and the lack of structured metadata make this description inadequate for an agent to select and invoke the tool correctly.

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 100%, so each parameter has a description in the schema. However, the tool description itself does not explain how the parameters relate to the tool's purpose. The schema descriptions are generic (e.g., 'Git ref name; discarded after the shape check') and do not clarify how they feed into a CityHash length computation. The description adds no semantic value beyond the schema.

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 'CityHash hex length, input discarded' is cryptic and does not state a clear verb or resource. It suggests the tool computes a CityHash hex length but does not explain what the tool actually does, what it returns, or how it relates to its siblings. The name 'cityhash-len' is not self-explanatory, and the description adds little beyond a vague hint about hashing and discarding input.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any conditions, exclusions, or sibling tools. The schema shows 9 optional parameters, but there is no explanation of which combinations are meaningful or when to prefer this tool over similar ones like 'search-query-len' or 'memory-key-count'.

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