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

With no annotations, the description carries the full behavioral burden. It adds a useful trait by saying conversions are exact and do not rely on lookup tables, but it does not disclose behavior for incompatible units, supported unit-string syntax, case sensitivity, or rounding.

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 front-loaded with the action and scope, followed by one concise exactness note. The unit-category list is long but earns its place by defining supported domains.

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?

An output schema exists, so return values need not be explained. However, for a three-parameter converter with no annotations and no schema parameter descriptions, the definition is only adequate: it covers unit domains but omits error behavior and exact unit-string conventions.

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%, so the description must compensate. It usefully lists the unit domains and gives compound-unit examples like kg/m^3 and mpg, but it does not explain the from_unit/to_unit string format, accepted abbreviations, or how value is interpreted.

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 and resource ("Convert a value between units") and enumerates supported unit categories, making the tool clearly a general physical-unit converter. It does not explicitly name or exclude nearby siblings such as crypto_convert or time_zone_convert, so it is clear but lacks explicit sibling differentiation.

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?

The list of supported unit categories implies when the tool is appropriate, but there is no explicit guidance on when to use it versus crypto_convert, fx_rates, or time_zone_convert. Usage is inferable rather than stated.

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