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

Annotations already cover readOnly, idempotent, non-destructive, closed-world behavior, so the safety bar is met. The description adds useful behavior beyond that: the conversion is to 'every common unit' and the stated purpose is downstream compatibility with growth tools, which tells the agent what to do with the result.

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?

Two sentences: purpose and downstream reason front-loaded, then two worked examples. No filler, and the examples are placed where the agent needs them to encode compound measurements.

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 output schema, the description still conveys that the output is the measurement expressed in every common unit, which is enough to use it. It does not spell out the exact return shape, but combined with full param coverage and clear annotations, an agent has what it needs to call it correctly.

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, but the description earns above that by demonstrating the awkward compound-input case the schema only abstracts: '7 lb 4 oz' maps to value 7, unit lb, extra 4. This clarifies the ambiguous 'extra' parameter beyond the schema's own wording.

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 (converts) and resource (weight in kg/g/lb/oz or length in cm/m/in/ft), and explicitly frames it as a utility feeding the growth tools. This clearly distinguishes it from the sibling percentile/age tools that consume the converted values.

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?

It gives concrete when-to-use context: converting a measurement quoted in lb/oz or ft/in so it can enter 'the growth tools, which take kg and cm.' That is a clear motivating scenario, though it does not name a specific sibling tool or state any exclusions.

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