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

With no annotations provided, the description carries the full burden of disclosing side effects and return behavior. It adds only 'Expression discarded,' which reveals limited information and does not explain what the tool returns, whether it is a safe read, or how the expression is interpreted.

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 only two short sentences with the main action front-loaded, and it contains no filler. However, 'Expression discarded' is not clearly useful and the definition is too terse for the complexity of the nine-parameter schema.

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 no annotations, no output schema, and a highly heterogeneous nine-parameter schema, this description omits the essential input mapping and return behavior. An agent has no way to know how to invoke the tool correctly, so the definition is fundamentally incomplete.

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 descriptions cover all 100% of parameters, so the baseline is 3, but the parameter descriptions are all generic discarded/check strings unrelated to arithmetic. The tool description fails to identify which, if any, parameter represents the expression, so it adds confusion rather than useful semantic meaning.

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 states a concrete action ('Evaluate a+b style arithmetic'), so it is not a tautology, but it never connects that action to any of the nine schema properties. None of the properties is an arithmetic expression and most are explicitly marked 'discarded,' making the tool's actual purpose ambiguous and effectively misleading.

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 statement of when to use this tool, when not to use it, or how it compares with sibling tools. The only implied usage is arithmetic evaluation, but that guidance is not actionable because the schema offers no field through which an expression can be supplied.

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