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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safe/pure-computation profile is fully covered. The description adds the valuable scope detail that units are UK-standard and lists what is returned, but adds nothing about limits, batch semantics, or validation behaviour beyond that.

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?

Prose is tight and front-loaded with the computation, but the final sentence pointing to list_bundles for 'cuisine' calculators is unrelated to alcohol-unit maths and does not earn 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 single-parameter computation tool with an output schema and full annotations, the essentials are present, and return values are covered by the output schema anyway. The remaining gap is the batch array/schema shape, which the description neither clarifies nor corrects.

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 carry the burden, yet it says 'Inputs: volume mL, ABV %' in the singular, while the schema requires an array of drink objects with type/volume_ml/abv_pct. It omits the 'drinks' array wrapper and the 'type' enum entirely, and its singular framing mildly misrepresents the accepted shape.

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 and resource ('Compute alcohol units (UK) and grams of pure alcohol'), which cleanly separates it from siblings like calculate_blood_alcohol or calculate_bac_points. It does not explicitly differentiate from those siblings, and the trailing 'See list_bundles for related cuisine calculators' pointer is off-topic rather than clarifying.

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?

Gives a use context ('health tracking and limit awareness') but no when-to-use-vs-alternative guidance, e.g., it never says how it differs from calculate_blood_alcohol or calculate_bac_points, which are close neighbours. Usage is implied rather than directed.

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