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

With no annotations, the description carries the full burden. It does add real behavioral value by disclosing exact BigInt arithmetic and no floating-point error for arbitrary magnitudes, plus the x402 cost. It omits what happens on invalid input, whether output is a string, and whether rounding/truncation ever occurs.

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?

Front-loaded and tight: the conversion scope and precision guarantee come first, followed by a compact pricing note. Two sentences plus a price tag, with negligible waste.

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?

No output schema and no annotations, so the description should cover more. It explains the computation contract but says nothing about the return shape, error behavior, or edge cases, leaving an agent to infer the output form.

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 coverage is 100%, so the baseline is 3. The description adds the unit vocabulary and the exact-precision intent for the value param, but the schema descriptions themselves are bare restatements ('From', 'To') and the value format is already in the schema. It also uses 'microether'/'milliether' while the enum uses 'microeth'/'millieth', which is a minor naming mismatch rather than added clarity.

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?

States a specific verb (Convert) and resource (wei/kwei/mwei/gwei/microether/milliether/ether) plus the mechanism (exact BigInt arithmetic). An agent can distinguish this from the generic converters_number_base_converter and from crypto_gas_fee_calculator without opening any schema.

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?

No statement of when to use this versus siblings such as crypto_gas_fee_calculator or converters_number_base_converter, and no prerequisites or exclusions. Usage is only implied by the tool name and the unit list.

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