convert

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description goes further by disclosing error semantics (cross-family requests fail loudly rather than returning nonsense) and the decimal-vs-binary convention for data units. It does not mention precision or rounding, which keeps it at 4 rather than 5.

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?

Three sentences, front-loaded with purpose before the constraint, then the unit vocabulary. The long unit list is information-dense rather than padding, and every clause earns its place.

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?

For a stateless, side-effect-free conversion with full annotation coverage, the definition gives everything needed to call it correctly. The only unmet detail is what the return value looks like (bare number vs object), which is not stated and no output schema exists to cover it.

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 descriptions are minimal ('Source unit', 'Target unit', 'Numeric value'), so the description carries real load by supplying the complete accepted vocabulary for from/to and disambiguating kb/mb/gb (1000) from kib/mib/gib (1024). This is meaningfully more than the 100%-covered schema provides.

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) plus the resource families (length, mass, time, data size) and then enumerates every supported unit, so an agent can tell at a glance that this is physical-unit conversion and not the sibling base_convert (numeric base conversion). No ambiguity about what it does.

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?

Usage is implied by the purpose and the constraint that from/to must belong to the same family ('cross-family conversions are rejected'), but there is no explicit when-to-use statement and no routing guidance against the closely related base_convert sibling. Adequate but leaves the alternative-selection decision to inference.

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