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

No annotations are supplied, so the description carries the full disclosure burden. The word 'safe' hints at sandboxing but does not explain what safety means in practice, nor does it cover error handling, numeric precision, input limits, or evaluation behavior.

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 definition is a single, front-loaded sentence fragment with no wasted words. It conveys the core operation and supported syntax immediately.

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?

There is no output schema and no annotations, yet the description does not state the return type, precision, or error behavior, all of which matter for an arithmetic evaluator. For this minimal tool, the description leaves important call-time expectations unstated.

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 0%, but the description partially compensates by listing the operators and 'parens' accepted by the expression. It still does not name or explicitly define the 'expr' parameter, but the operator set gives meaningful context for what the string parameter contains.

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 operation (arithmetic eval) and enumerates supported operators, so the agent knows this is an expression evaluator. It does not explicitly distinguish itself from sibling tools, but among the listed siblings none directly overlap with arithmetic evaluation.

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?

No when-to-use guidance, no exclusions, and no named alternatives are provided. The purpose implies a generic arithmetic use case, but the description offers nothing to help an agent choose this tool over other numeric or date_calc siblings.

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