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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine value beyond that by disclosing the full computation chain (average depth, volume ÷12, waste multiplier, yield division), letting the agent verify how the number is produced rather than treating it as a black box.

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?

The purpose statement is front-loaded and the formula chain is compact and scannable. The trailing 'Coverage at 1/4 in = yield ÷ (0.25 ÷ 12)' is somewhat tangential since no coverage parameter or output field is referenced, making it the one sentence that doesn't fully 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?

All five parameters are optional with defaults, and the formula makes the calculation reproducible. With no output schema, a small gap remains: the description doesn't state whether the result is rounded up to whole bags or that volume/coverage figures may also be returned.

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 baseline is 3, but the description earns an extra point by showing how each parameter enters the formula: waste_pct is applied as a multiplicative allowance (1 + allowance), depths are averaged, and bag_yield_cuft is divided out. That explains the direction and units of each input more concretely than the schema strings.

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 specific verb+resource: how many bags of self-leveling underlayment/floor resurfacer to buy, and names the exact inputs it derives that from. An agent can tell this apart from calc_concrete_slab, calc_thinset, or calc_epoxy_floor without opening the schema.

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?

The usage context is implied by the inputs ('from your floor area and the thinnest and thickest pour depth'), so an agent can infer this is for a pour over an existing slab. However, no sibling is named and there is no explicit when-to-use/when-not guidance (e.g. versus thinset or concrete slab calculators).

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