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

No annotations are provided, so the description carries the full burden. It discloses that conversions are deterministic and restricted to length, mass, and temperature, and excludes currencies/timestamps. However, it does not mention unit format expectations (e.g., abbreviations, case sensitivity), error handling for unsupported units, or whether output is numeric, which are relevant behavioral details for an agent.

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 and well-structured: a clear opening sentence, a bulleted 'Use when' with three concrete examples, and a 'Do not use when' list. Every sentence contributes information without redundancy, and the use-case guidance is front-loaded.

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 straightforward conversion tool, the description covers purpose, categories, examples, and exclusions. It does not explicitly state the return format (e.g., number) or list all units, but given the lack of an output schema, these are minor gaps that do not prevent correct invocation in most common cases.

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 there are no enums, so the description must compensate. It does so by giving examples (miles, kilometers, Celsius, Fahrenheit) and implicitly mapping '10 miles' to value, from_unit, and to_unit. However, it does not enumerate the full set of supported units or clarify input formatting (e.g., symbol vs full name, case sensitivity), leaving ambiguity for arbitrary unit strings.

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 opens with a specific verb ('Convert') and resource ('numeric value between supported length, mass, or temperature units'), provides concrete examples (miles to kilometers, Celsius to Fahrenheit), and clearly distinguishes itself from sibling conversion tools like currency_lookup, timestamp_convert, and timezone_convert by naming their scopes.

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?

Includes explicit 'Use when' and 'Do not use when' sections. It names alternative tools for excluded categories (currency_lookup for currencies, timestamp_convert/timezone_convert for time) and provides concrete user queries to illustrate appropriate usage, giving strong selection guidance.

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