unit_calculate

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

With no annotations, the description carries the full burden: it says it returns a value and unit but omits what happens with dimension mismatches, which units are supported, accepted syntax, or error behavior. It discloses the return shape but little else about operation.

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?

A single efficient sentence with the action and result front-loaded; nothing is wasted. For a one-parameter tool this length is appropriate, though the brevity leaves substance missing rather than being a flaw of verbosity.

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?

With no annotations, no output schema, and 0% schema coverage on the only parameter, the definition should supply syntax guidance and error semantics. It does not, so an agent cannot reliably call it correctly for non-trivial expressions.

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 0% and the single 'expression' parameter has no description anywhere. The description implies it is a unit-bearing arithmetic expression but gives no syntax or format examples (e.g., '3 m + 2 ft'), so it fails to compensate for the coverage gap.

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 (evaluate) and resource (unit-bearing arithmetic expression) and clarifies the return (value and unit). It is distinguishable from sibling unit_convert, but the description never explicitly differentiates the two, so it falls short of 5.

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?

There is no guidance on when to use this versus alternatives such as unit_convert, symbolic_evaluate, or matrix_compute. No prerequisites or conditions are given, leaving usage entirely to inference from the name.

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