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

Annotations already declare readOnlyHint, non-destructive and closed-world, so the safety profile is fully covered. The description adds nothing beyond that — no note on how zero or negative integers are handled, no error behavior, no statement that a result is returned immediately. For a pure computation this is tolerable but still empty.

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 front-loaded sentence with no filler. It is efficient, though the brevity shades into under-specification rather than disciplined concision.

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 and annotations exist, so return values and safety need not be described. However, with zero required parameters, the description should at least say that either a+b or the numbers array must be supplied — otherwise an agent could legally invoke it with an empty object.

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% and every property carries a description plus examples, so the baseline is 3. The description does not resolve the real ambiguity: all three parameters are optional, and the schema labels a and b only as 'alt', so nothing tells the agent whether a/b are an alternative to the numbers array or can be combined.

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?

Names a specific mathematical resource (Least Common Multiple) and its domain (two or more integers), which is unambiguous. It does not distinguish itself from the closest sibling, calculator_gcd, which an agent might reasonably confuse it with in a list of 140+ calculators.

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?

There is no guidance on when to use this versus calculator_gcd, calculator_prime_factors, or calculator_factor. Nothing explains which input form to choose (a/b pair vs. numbers array), which is the only real decision the caller faces.

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