get_function_selector

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The one-sentence description states the computation but does not specify the output format (e.g., whether it returns a 0x-prefixed hex string), how invalid signatures are handled, or whether input normalization is applied. This leaves important behavior undisclosed.

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 a single, front-loaded sentence that immediately conveys the tool's purpose with no redundant content. It is appropriately sized for a simple utility.

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 simple compute utility, the description and complete schema cover the essential input, but since there is no output schema and no annotations, the lack of any detail about the return value format or edge cases leaves a notable information gap. The straightforward nature of the tool mitigates this, but it is not fully complete.

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%, and the 'signature' parameter is clearly documented with a representative example. The tool description adds no additional semantics beyond the schema, so the baseline score of 3 is appropriate.

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 uses a specific verb 'Compute' and identifies the exact resource '4-byte function selector' with the input 'Solidity function signature'. This clearly distinguishes it from sibling tools like calculate_event_signature, which targets event signatures, and keccak256_hash, which is a general hashing function.

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 when to use the tool—whenever a 4-byte function selector is needed—but provides no explicit comparison with alternative tools or guidance on when not to use it. There is no mention of how it relates to similar tools like calculate_event_signature or get_event_topic.

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