unit_converter

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

Annotations already declare readOnlyHint=true and idempotentHint=true, indicating no side effects. The description adds context about supported units and notes on ton definitions but does not disclose additional behavioral traits like error handling or precision. The bar is lowered by annotations, so a 3 is appropriate.

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 well-structured with a summary, bullet points, and a note. It front-loads the main purpose and uses concise language. Slightly verbose but efficient for the information provided.

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?

Given the complexity and no output schema, the description covers the tool's capabilities, including special freight conversions. It omits error cases and precision details, but for a conversion tool this is fairly 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 coverage is 100%, so the schema documents all parameters well. The description adds meaning by explaining that chargeable_kg and freight_tonnes are only valid from cbm, a constraint not captured in the schema enums. This adds value 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 clearly states 'Convert between freight and logistics units' and lists supported unit categories. It distinguishes itself from siblings like cbm_calculator by including freight-specific conversions, but does not explicitly differentiate between this and dedicated calculators for overlapping conversions.

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 provides explicit use cases (convert metric/imperial, calculate freight tonnes from CBM, convert CBM to chargeable weight). However, it lacks guidance on when not to use this tool or alternatives, such as the chargeable_weight_calculator or cbm_calculator.

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