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

The only behavioral cue is 'Expression discarded,' implying no retention of the expression, but no annotations are provided to supplement this. There is no mention of side effects, input validation, or error behavior, which is insufficient for a tool with nine optional 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 extremely concise, using only two short sentences with no superfluous words or redundant information. It is well-structured for its brevity, though that brevity contributes to other deficiencies.

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 the tool has nine optional parameters, all with seemingly irrelevant descriptions, the description fails to provide any coherent context on how these parameters relate to arithmetic evaluation. The tool is effectively unusable as described, lacking essential instructions on parameter usage and expected output.

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?

The schema descriptions are present but entirely mismatched with the tool's purpose (e.g., 'Git ref name,' 'HTTPS URL,' 'City name'). The description does not clarify which parameter holds the arithmetic expression, making it impossible to know how to construct a valid call. This is a critical gap.

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 clearly states the tool evaluates 'a+b style arithmetic,' which is a specific action on a specific resource. However, it doesn't differentiate from sibling tools that might also handle numeric operations, and the parameter list is unrelated, creating confusion about the actual 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 on when to use this tool versus alternatives. It doesn't mention conditions, prerequisites, or scenarios where arithmetic evaluation is preferred over other operations, leaving the agent without context for selection.

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