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

No annotations are provided, and the description only says 'Expression discarded,' which is insufficient. It does not disclose what the tool returns, whether it has side effects, how it handles invalid input, or what it does with the other supplied parameters.

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 and avoids unnecessary words, but the second sentence adds confusion rather than clarity. Conciseness is undermined by the absence of any usable invocation structure.

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 no output schema and a description that does not explain return format, error behavior, or parameter roles, the tool is incomplete from an agent's perspective. The unrelated optional parameters only increase ambiguity.

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?

All nine parameters have individual descriptions, but those descriptions are unrelated to arithmetic and mention things like Git refs, URLs, timezones, and JSON validation. There is no expression parameter, so the parameter list does not support the stated purpose.

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 an operation ('Evaluate a+b style arithmetic'), but the schema contains no expression parameter, so an agent cannot tell what input should be evaluated. The added sentence 'Expression discarded' further muddies the intended purpose.

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 instead of the many sibling tools, nor is there an example or explanation of how the listed parameters relate to arithmetic evaluation. An agent has no way to know how to construct a valid call.

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