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

Beyond the annotations (readOnly, idempotent, non-destructive, openWorld), the description adds key behavioral details: exact integer arithmetic with no floating-point rounding, refusal of conversions that would drop digits, and a specific per-call price via x402. These are material facts an agent needs before invoking the tool.

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 short and front-loaded, with the core purpose first, then behavioral detail, then pricing. The opening sentence largely repeats the title, which is slightly redundant, but the remaining content is efficient.

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 low-complexity read-only conversion tool with no output schema, the description is sufficiently complete: it covers supported units, precision behavior, refusal semantics, and cost. Nothing critical for correct invocation is missing.

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 only 33%, so the description must compensate. It does by explaining the unit/decimals space for from/to (wei, gwei, ether, or 0-36 decimals such as 6 for USDC) and the exactness constraint on the value, though it does not clarify defaults or value formatting 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 states a specific verb and resource: exact conversion of amounts between wei, gwei, ether, or any token decimals. It clearly distinguishes itself from general sibling tools like unit_convert and currency_convert by naming crypto-specific units and exact integer arithmetic.

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 the tool applies (crypto unit conversions and token decimals 0-36), but it does not explicitly say when to use it versus siblings like unit_convert or currency_convert, nor does it state exclusions. Usage is inferable but not spelled out.

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