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

The description claims arithmetic evaluation, but the schema has no parameter to supply an expression. This is a direct contradiction between the description and the schema's parameter set. Since no annotations are provided, the description carries the full burden, and it fails to disclose what happens to the input parameters, what the tool returns, or any side effects. The phrase 'Expression discarded' suggests an expression is input, but no such parameter exists.

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 (one sentence plus a fragment), which is good, but it lacks substance. It is not front-loaded with the most critical information, and the second clause ('Expression discarded') is confusing given the schema. Conciseness is not the issue; the content is insufficient.

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 9 parameters and no output schema, the description is completely inadequate. It fails to explain why these parameters exist, how to use them, what the tool returns, or any edge cases. An agent cannot correctly invoke this tool based on the given definition.

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 coverage is 100%, so all parameters have descriptions in the schema. However, the tool description does not explain how any of these parameters relate to arithmetic evaluation. It adds no meaning beyond the schema, and actually introduces a false expectation about an 'expression' parameter. The description does not help an agent understand how to use the 9 parameters for 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 states a clear purpose ('Evaluate a+b style arithmetic'), but it does not align with the actual input schema, which contains parameters like URL, city, timezone, and JSON. This creates confusion about what the tool actually does, and there is no differentiation from sibling tools, which are all URL/timezone/validation oriented.

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. The description does not mention any context, prerequisites, or exclusions. An agent has no idea when calc-eval is the right choice over other tools.

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