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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered. The description adds that a waste margin is incorporated and that pallets are returned, but with an output schema present the return-value note carries limited weight and no caveats (e.g., what waste % is assumed, rounding) are disclosed.

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?

Three short sentences, front-loaded with the core computation and efficient overall. The "Inputs:" sentence is a compact enumeration style, but its content is inaccurate, which undercuts the value of the space it occupies.

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?

An output schema exists so return values need not be explained, and the masonry framing is adequate. However, the description implies inputs that the schema does not accept and omits that the waste margin and brick size are fixed internally rather than user-supplied, leaving a real ambiguity for invocation.

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 schema is fully documented and defines type/height_m/length_m, but the description's "Inputs: wall dimensions, brick size, waste %" names two inputs (brick size, waste %) that do not exist in the schema, which forbids additional properties. An agent may attempt to pass those phantom parameters and fail, so the description misleads rather than clarifies.

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+scope: compute bricks or blocks needed for a wall including a waste margin. It also distinguishes itself from the vast sibling set by pointing to list_bundles for related 'construction' calculators, so an agent can place it 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?

"Use for masonry projects" gives clear usage context and the list_bundles pointer routes agents to related tools. There is no explicit when-not or alternative masonry calculator named, so it stops short of a 5.

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