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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered. The description only adds the unit of measurement and the intended consumer of the data; it says nothing about how many home sizes are returned or the shape of the entries.

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?

One sentence, front-loaded with the resource and its unit, with the purpose clause trailing. Nothing redundant and no filler.

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 zero-parameter static lookup with annotations covering its safety profile, the description is nearly sufficient: an agent knows what it returns conceptually (volumes by home size, in cubic metres) and why. The only gap is the absence of an output schema or any mention of the available home-size buckets.

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?

The tool takes zero parameters, so the baseline is 4. The description does add useful downstream meaning by naming volume_m3 on get_moving_estimate as the value this output feeds.

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 the specific resource (typical moving volumes in cubic metres, per home size) with a clear lookup intent, and explicitly distinguishes itself from the sibling get_moving_estimate by positioning itself as the input-selection aid.

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 clear when: use this to choose the volume_m3 value that get_moving_estimate needs, naming the sibling explicitly. It stops short of stating exclusions (e.g. when the user already knows their volume), so it is not fully exhaustive.

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