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

No annotations are provided, so the description carries full responsibility for disclosing behavior. It merely says 'Expression discarded,' which is cryptic and does not explain what the tool actually does with the inputs (e.g., shape checking) or any side effects. This is misleading and incomplete.

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 extremely short, which could be seen as concise, but it omits essential information. It lacks structure and fails to front-load key details, making it under-specified rather than elegantly concise.

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?

With 9 parameters, no output schema, and no annotations, the description is wholly inadequate. It does not explain what the tool does with the parameters, what result is returned, or how the 'discarded' inputs are handled. An agent cannot call this tool correctly based on the given information.

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?

While the schema descriptions are explicit (each param is discarded after a shape check), the tool description claims arithmetic evaluation, which does not map to any of the parameters. The description adds no meaningful explanation of how the parameters relate to the tool's purpose and actively misleads about their usage.

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 specific verb and resource ('Evaluate a+b style arithmetic'), but it is unclear how this relates to the 9 parameters, none of which represent an arithmetic expression. It also fails to differentiate from sibling validation tools like domain-shape or file-path-ok, leaving the agent uncertain about the tool's actual function.

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 tool or when to prefer alternatives. The description provides no context, prerequisites, or exclusions, so an agent cannot determine the appropriate invocation scenario.

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