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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is fully covered. The description adds useful behavior beyond that (dual-unit results and premix bag counts), but says nothing about edge cases, defaults, or output shape. Adequate, not rich.

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 sentences, with the substantive scope statement front-loaded before the link. The trailing marketing URL is low-value filler, but the rest earns its place with no redundancy.

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 read-only, fully-schema-documented calculator with no output schema, the description supplies the key missing piece: what the tool returns (volume in two unit systems plus bag counts). It stops short of noting that all parameters have defaults or that the schema coverage is complete, but an agent has enough to call it correctly.

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 nine parameters are already documented in the schema. The description reinforces the domain meaning of the outputs (cubic yards vs cubic meters, 40/60/80 lb and 25 kg bags) but adds no format or constraint detail beyond what the schema provides. Baseline 3 applies.

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?

The description names a specific resource (concrete) and enumerates the scenarios it covers (slabs, wall footings, post holes) plus the exact outputs (cubic yards/meters, premix bag counts by weight). This is far more than a restatement of the name, though it does not explicitly distinguish itself from adjacent siblings such as gravel_calculator or volume_calculator.

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 enumerated job types (slab, footing, post hole) and the growing-context bag-sizing output, so an agent can infer when the tool applies. There is, however, no explicit when-to-use statement and no mention of alternatives like gravel_calculator or area_calculator for related material-estimate needs.

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