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

With no annotations provided, the description carries the full burden of explaining side effects, persistence, errors, and return behavior. It only vaguely says the expression is discarded, and the schema parameter descriptions contradict the arithmetic purpose by referencing unrelated 'shape checks' and discarded values.

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 short, which is efficient, but it omits the most essential information about how to provide the expression. Being brief at the cost of correctness and usefulness is not effective structuring.

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?

Given 9 parameters, no output schema, and no annotations, the description is far from complete. It fails to explain how the parameters relate to arithmetic evaluation, what the tool returns, or what 'discarded' means for the caller.

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?

Although all 9 parameters have schema descriptions, those descriptions are nonsensical in the context of arithmetic evaluation, e.g. 'Git ref name; discarded after the shape check' and 'JSON text to validate; discarded after the check'. No parameter is described as the expression to evaluate, so the schema adds confusion rather than 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 claims the tool evaluates 'a+b style arithmetic', but the input schema contains no expression parameter; instead it lists unrelated parameters like ref, url, city, and feed. It does not indicate which parameter carries the arithmetic expression, and it fails to distinguish this tool from siblings such as validate-json or normalize-url.

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 guidance is given for when to use this tool, how to structure an arithmetic call, or which parameter is required. The phrase 'Expression discarded' is confusing rather than instructive, and there are no examples or prerequisites.

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