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

Annotations already signal a safe, read-only, idempotent operation; the description adds determinism ('exact'), single-call batching, and the fact that input may itself be hex/base64/base58. It does not fully specify output representation, but the annotations carry the safety burden.

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?

Three dense sentences with no filler; the capability is front-loaded, followed by use cases and the input caveat. 'Price: free' is a minimal and useful contextual note.

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?

The description is sufficient for choosing the tool and for basic invocation, but with no output schema it leaves the return format ambiguous and never says how to request one of the advertised encodings as output. The base64url/input_encoding inconsistency also creates a small completeness 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?

It lists algorithms and encodings and clarifies that input can be encoded, adding some meaning to `hashes` and `input_encoding`. But the mapping to parameters is implicit, base64url is mentioned without a corresponding enum/parameter, and output encoding is never explained, so the description only partially compensates for the 50% schema coverage.

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?

Opens with a specific action ('Hash data... and convert between...'), enumerates the algorithm families and encoding formats, and adds 'exact, in one call' so it is clearly distinct from sibling conversion/analysis tools.

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?

Names concrete use cases (signatures, content addressing, EVM selectors, decoding blobs), which tells an agent when to reach for it. It doesn't explicitly state exclusions or alternatives, but no sibling directly overlaps.

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