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

No annotations are provided, so the description carries the full burden. It discloses that the expression is 'discarded,' which hints at not retaining input, but it does not state whether the result is returned, whether there are side effects, what happens for invalid expressions, or any safety-relevant behavior.

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 and front-loaded, with the core action in the first sentence. However, it is under-specified: 'Expression discarded' raises more questions than it answers, and the absence of parameter mapping makes the brevity a liability rather than a strength.

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?

For a tool with seven string parameters, no annotation coverage, and no output schema, this description is far too incomplete. It does not explain how any schema field relates to arithmetic evaluation, what the tool returns, or how to construct a valid call, so an agent cannot reliably invoke it.

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 input schema richly describes its seven parameters, but none of them obviously corresponds to an arithmetic expression. The description introduces 'a+b style arithmetic' without mapping it to any schema field, leaving the agent unable to determine which parameter should contain the expression. This is a critical semantic gap beyond what the schema provides.

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 action ('Evaluate') and a specific resource ('a+b style arithmetic'), making the tool's core purpose clear. It also implicitly differentiates from the sibling validation/shape-check tools, none of which are arithmetic evaluators.

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 calc-eval instead of siblings, no example invocation, and no mention of prerequisites or alternatives. The only usable instruction is the action itself, which is not enough to choose between tools confidently.

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