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

Annotations already declare readOnly, idempotent, closed-world and non-destructive behavior, so the safety profile is covered. The description adds genuine value beyond that by disclosing exact BigInt arithmetic (no floating-point rounding) and that outputs include complete prime factorizations, which an agent cannot learn from the annotations.

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?

A single sentence that front-loads the operation, the input bounds, and the two notable behavioral traits before any trailing detail. Zero filler and nothing redundant.

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?

With an output schema present, return values need no explanation, and the annotations cover the safety profile; the description usefully supplements with precision and scope. Only minor gaps remain, such as what happens on out-of-range or non-integer input, which the schema pattern implies but does not state.

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%: the single parameter already documents the ±10^12 range, the no-separators/no-exponents rule, and exact BigInt parsing. The description's "2–20 integers" merely restates the schema's minItems/maxItems, adding no syntax or format detail beyond it, so the 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?

States a specific verb ("Compute") and resource ("least common multiple") with an explicit input scope of 2–20 integers, so an agent can tell what the tool returns. It does not, however, distinguish itself from the closely related sibling gcf_calculator or from prime_number_checker, which share the same numeric domain.

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 2–20 integer scope implicitly signals when the tool applies, but the description never states when to prefer it over gcf_calculator, fraction_calculator, or prime_number_checker, and offers no exclusions. Usage must be inferred from the domain constraint alone.

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