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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says 'Expression discarded,' which reveals that input is not retained, but it does not explain whether the tool returns a result, executes code, reads files, performs network calls, or has side effects. This is especially important for a tool named 'calc-eval.'

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 very short and front-loaded, with the core action in the first sentence. There is no filler or redundant information, though the second sentence is cryptic rather than merely 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?

This tool has nine heterogeneous optional parameters, no annotations, and no output schema. The description neither explains how any of those parameters relates to evaluating arithmetic nor states what happens on success or failure. An agent cannot reasonably determine how to invoke this tool correctly from the available 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?

Schema description coverage is 100%, so the baseline of 3 applies; each parameter already has its own meaning in the schema. However, the tool description adds no mapping between 'a+b style arithmetic' and any parameter, so it does not help the agent decide which field should contain the expression.

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 a concrete action ('Evaluate') and a resource ('a+b style arithmetic'), so the core purpose is understandable on its own. However, the phrase 'Expression discarded' is ambiguous, and none of the nine input parameters appears to hold an arithmetic expression, making it hard to connect the stated purpose to the actual schema.

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 about when to use calc-eval versus any of its many siblings, no mention of alternatives, and no context such as 'use when validating arithmetic shape' or 'use instead of calculator tools.' The agent is given no help in choosing this tool over other options.

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