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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description still adds value by clarifying "it sends nothing to anyone" (no external side effects) and by enumerating the return verdicts (fits/tight/ask/no), which annotations cannot convey. It stops short of describing limits or edge behavior for out-of-range dimensions.

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 question, then inputs, then returns and safety. Every sentence carries information an agent needs and none is padding.

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?

With no output schema, the description compensates by naming the return contents (overall verdict, per-model verdict, which measurement is short) and enumerating the possible verdict values. Combined with annotations covering the safety profile and a 100%-covered schema, nothing needed to invoke or interpret the tool is missing.

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%, so all three dimensions are already documented with bounds and orientation (e.g. depth measured from the folding wall). The description only adds the "whole inches" unit hint and names the three measurements, which the schema already conveys; baseline 3 is appropriate.

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?

Opens with a concrete question that states the exact task (checking whether a Duffer fits a room) and names the resource (Duffer golf bay vs. room dimensions). It is trivially distinguishable from siblings like list_models or find_dealers, and further specifies input units and return shape.

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?

"Will a Duffer fit a room? Give the room's width, depth and ceiling height in whole inches" makes the use case and the required input context clear, and "whole inches" tells the agent how to format input. It does not name alternatives or an explicit when-not-to-use, but the sibling tools are unrelated so no routing ambiguity exists.

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