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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds the supported unit list, but this is already present in the schema enums, providing no extra behavioral context beyond what is structured.

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 a single front-loaded sentence that names the operation and enumerates the relevant units. There is no redundancy or wasted words.

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?

The tool is a simple pure conversion with all parameters required and documented, output schema present, and annotations covering safety. The description is sufficient for the agent to understand and invoke the tool without additional behavioral details.

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 100%: each parameter has a description and the enums list all units. The description merely repeats the unit list without adding meaning beyond the schema, so it meets the baseline for full coverage but no more.

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 the exact operation ('Convert between volume units') and lists all supported units, which distinguishes it from other converter sibling tools (e.g., length-converter, temperature-converter). This fully clarifies the tool's purpose.

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 description clearly implies when to use the tool (any volume conversion) and the unit list makes its scope obvious relative to sibling converters. It lacks explicit exclusions or alternative recommendations, so it does not reach the 5-level.

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