function_selector

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

The description accurately reflects the tool's behavior as a deterministic computation with no side effects. Since no annotations are provided, the description carries full burden and does so clearly without misleading information.

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 concise: a single sentence that includes the core purpose and an illustrative example. Every word adds value, with no redundancy.

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 single-parameter tool with no output schema, the description is complete. It explains the input format, the operation performed, and provides an example, leaving no ambiguity about usage.

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 provides no description for the 'signature' parameter (0% coverage). The description adds semantic meaning by specifying the format as a function signature with an example, fully compensating for the lack of schema documentation.

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's function using a specific verb ('Compute') and resource ('4-byte selector for a function signature'), and provides a concrete example. It effectively distinguishes itself from sibling tools like keccak_hash or encode_abi.

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 usage (computing a function selector from a signature) but does not explicitly state when to use it over alternatives or provide exclusions. Given the variety of sibling encoding/hashing tools, more explicit guidance could help.

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