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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds genuine behavioral context beyond that: a 10% pattern-matching allowance and the return shape. It does not mention assumptions about fabric width, which matters for yardage.

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?

Three short sentences, front-loaded with the core action and the unit, then the pattern-matching caveat and return shape, then a cross-reference. No filler; every sentence earns 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 two-enum-param calculator with an output schema and full annotations, the description supplies what is needed to invoke it. The one real gap is disambiguation from calculate_fabric_needed, which the description does not address.

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%, but both parameters are closed enums with self-explanatory values (garment: shirt/dress/pants/skirt/jacket; size: S/M/L/XL). The description frames the input as 'for a garment in meters' but adds no syntax or constraint detail; the enums carry the meaning.

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+resource+unit: 'Calculate fabric needed for a garment in meters.' Clear what it does. However, it does not distinguish itself from the near-identical sibling calculate_fabric_needed (nor calculate_curtain_fabric / calculate_knitting_yarn), so an agent cannot tell which fabric tool to pick from the description alone.

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?

No when-to-use, when-not, or prerequisite guidance. The pointer 'See list_bundles for related textile-mode calculators' gestures at a family but never says when this tool applies versus calculate_fabric_needed, leaving selection to inference.

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