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

No annotations exist, so the description must describe behavior on its own. It only says the expression is discarded, while saying nothing about return values, side effects, permissions, or whether any of the 9 parameters are actually consumed.

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?

The description is very short, begins with the main purpose, and contains no filler or redundancy. The second sentence is ambiguous but not bloated; the conciseness itself is good.

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 tool with 9 optional parameters, no annotations, and no output schema, this two-sentence description is far too thin. It does not explain why the parameters exist, how to supply the arithmetic expression, or what a successful call returns.

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 high and the schema parameters are individually described, which would warrant a baseline of 3. But none of the schema parameters clearly carries the arithmetic expression central to the tool, and the description does not map 'expression' to any input field.

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 concrete operation, 'Evaluate a+b-style arithmetic', so it is not just a tautology. However, it never connects that arithmetic expression to any of the 9 schema parameters, and the phrase 'Expression discarded' adds ambiguity about whether an expression is accepted at all.

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 description provides no guidance on when to use this tool instead of the many sibling validators and checkers. It gives no conditions, exclusions, or alternative tool references.

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