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

Discloses the tool is deterministic and mentions a 400 error for different-dimension conversions, which adds behavioral insight beyond the absent annotations. However, output format and handling of invalid unit strings are unspecified.

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 compact yet information-rich: free usage, determinism, dimensions, args, examples, and an error behavior are all included without redundancy. The minor typo 'Different-dimension conversions 400' does not detract from clarity.

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 straightforward 3-parameter tool with no output schema and no annotations, the description covers purpose, usage, examples, and one edge case. Return value format is not specified, but the intent is clear for this simple conversion tool.

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 all parameters with short descriptions, but the description adds concrete examples (e.g., from:'c', to:'f', GiB to MB) that clarify unit notation and the numeric value type. This goes beyond the schema baseline.

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?

Clearly states the tool converts a value between units in the same dimension and enumerates dimensions (length, mass, temperature, etc.). This specific verb-resource pairing distinguishes it from sibling tools like currency and datemath.

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?

Indicates usage for unit conversion across multiple dimensions, but does not explicitly state when not to use (e.g., currency conversions may be handled by the 'currency' sibling). The dimension list implies when to use, but exclusions are absent.

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