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

With no annotations, the description must carry behavioral disclosure. It mentions only that an expression is discarded; it does not state what is returned, whether calls are side-effect free, how the schema fields are used, or any error/limit 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 short and front-loaded, but the second sentence is cryptic and the whole description is under-sized relative to a nine-parameter schema. This is under-specification rather than disciplined conciseness.

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 nine parameters, no annotations, no output schema, and no return-value specification, the description is functionally incomplete. An agent cannot determine what to pass, what the result contains, or whether this is even the correct tool for arithmetic evaluation.

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%, so a baseline of 3 applies. The tool description adds no parameter-level meaning and mentions an 'expression' that is not in the schema, but the schema's own descriptions already document each property.

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 a tautology, but it never connects that operation to any of the nine input properties. 'Expression discarded' adds confusion rather than clarifying what input carries the expression.

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 when-to-use or when-not-to-use guidance and no reference to any sibling tool or alternative. The only implied context is arithmetic evaluation, which cannot be reliably acted on because the schema exposes no expression parameter.

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