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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered without description help. The description adds the accepted unit vocabulary and pins 'US cup (240 mL)', which is genuinely useful disambiguation, but says nothing about precision, rounding, or invalid-unit handling.

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 front-loaded fragment with zero filler: verb, resource, and the supported unit set. Nothing could be removed without losing information.

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 no explanation, and annotations cover the safety profile. What remains slightly incomplete is the boundary against sibling conversion tools and which unit spellings are valid.

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 would be 3, but the parameters carry no enum constraints and the description supplies the actual accepted unit strings (mL, L, US gallon, US cup, m³). That meaningfully compensates for the missing enums, though it doesn't say whether aliases like 'gallon' or 'liter' are accepted.

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) and resource (volume) plus the supported units, so the intent is unambiguous. It does not, however, distinguish itself from generic siblings such as calculator_convert or calculator_unit_constants, which an agent must infer the boundary against.

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 only implied by the unit list: an agent can infer this is for volume unit conversion. There is no explicit guidance on when to prefer this over calculator_convert (generic conversion) or calculator_volume (volume computation), and no prerequisites or exclusions are stated.

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