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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description goes beyond that by disclosing the deterministic computation behavior and the outputs produced (paver count plus cubic yards), which is useful context for a calculation tool.

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?

Two dense sentences: the purpose/scope is front-loaded, then the exact formulas follow. No filler, no repetition of schema fields, and the formula detail earns its place for a calculator.

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 7-parameter, zero-required, read-only calculator with no output schema, the description covers purpose, method, and the quantities returned. It is nearly complete; only explicit output units/format naming is left implicit.

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% with defaults on all seven parameters, so the schema carries parameter meaning. The formulas imply how waste_pct, base_depth_in, and sand_depth_in are consumed, but this adds only marginal meaning beyond the already-complete schema. 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?

States a specific verb+resource: pavers count for patio/walkway/driveway plus cubic yards of compacted base and bedding sand. This clearly distinguishes it from the many sibling calculators (calc_mulch_gravel, calc_asphalt, calc_concrete_slab, etc.) by naming the exact material and derived quantities.

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?

Usage is implied by the resource named (compute materials for a paver project), but there is no explicit when-to-use, when-not-to-use, or pointer to an alternative sibling calculator. No prerequisites or exclusions are stated.

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