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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds a real usage constraint (all three dimensions must exist), but never says what is returned — a price value, currency, or per-unit vs. total — which matters for a calculation tool with no output schema.

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?

Four short sentences, front-loaded with purpose then the gating condition. Minor redundancy: the decimal-point/unit instruction duplicates what the schema already states three times.

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 computation tool with no output schema, the agent still needs to know what the result looks like (number? formatted price? includes quantity?). The precondition is covered but the return contract is not, leaving a meaningful 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 every parameter is already documented, including unit and decimal-point guidance. The description's repetition of 'no cm unit, use a decimal point' adds no meaning beyond the schema and never mentions the optional quantity parameter.

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 and resource: it calculates the price of a custom cuboid/block or array. That distinguishes it implicitly from the generic get_product_price sibling, but the description never names that sibling or explicitly contrasts the two.

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?

Gives an explicit precondition: only call when the customer has supplied all three required dimensions. It lacks a clear pointer to an alternative (e.g., get_product_price for standard products), so the use-vs-alternative routing is left implicit.

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