hash_message

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. It only mentions the hashing format but does not disclose the output format (e.g., hex string), the exact EIP-191 prefix behavior, or any edge cases. For a simple, non-mutating hash operation, this is minimal but not completely absent.

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 with no wasted words. It immediately conveys the tool's core function.

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?

There is no output schema, and the description does not explain what the tool returns (e.g., a hex-encoded hash) or any nuances of EIP-191 hashing. Given the large sibling tool list and the absence of annotations, the description is insufficient for an agent to fully understand the tool's behavior without prior knowledge. Complexity is low, but the missing return format and format specifics create a clear gap.

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 covers the only parameter 'message' with a description, and the tool description adds the EIP-191 format context, which clarifies the hashing algorithm. However, the description does not add parameter-specific details such as expected encoding (e.g., UTF-8) or handling of large messages. With 100% schema coverage, the baseline is 3 and the description only marginally extends it.

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 action (hash), the resource (message), and the specific format (EIP-191), distinguishing it from raw hashing tools like keccak256_hash and structured data hashing like hash_typed_data. This is a specific verb+resource+format combination.

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 guidance on when to use this tool versus alternatives such as keccak256_hash, sign_message, or hash_typed_data. The description only states what it does, leaving the agent to infer when EIP-191 hashing is appropriate. No exclusions or alternative recommendations are provided.

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