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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds that the computation includes a waste margin and returns recommended buying, which is mildly useful, but offers nothing on rounding, units, or edge cases beyond the annotations.

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?

Purpose is front-loaded and the text is short, but the 'Inputs:' sentence is inaccurate and wastes space naming parameters that don't exist rather than adding value.

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 an output schema present, return values needn't be detailed, and for a read-only calculator the annotated safety profile suffices. Still, the description neither differentiates from calculate_paint_quantity nor accurately reflects the actual input set, leaving a real gap.

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 coverage is 100%, so a baseline of 3 would apply if the description stayed silent. Instead it lists 'Inputs: room dimensions, coats, openings' — 'openings' is not a parameter at all and 'coverage' (m²/liter) goes unmentioned, so the description actively misrepresents the inputs.

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 ('Compute paint quantity for walls') and adds scope detail (coats, waste margin, liters). However, it does not distinguish itself from the near-identical sibling calculate_paint_quantity, leaving the agent unable to tell the two apart.

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?

'Use for renovation budget' gives a loose context, and it points to list_bundles for related construction calculators. But it gives no guidance on when to pick this over calculate_paint_quantity, its closest sibling, so usage is only implied.

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