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

With no annotations and a self-contradictory description, the tool's behavior is not transparent; 'Expression discarded' conflicts with 'Evaluate ... arithmetic' and the schema parameters are described as discarded.

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 but wastes words on a contradictory note ('Expression discarded') and omits critical invocation details for the intended arithmetic operation.

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?

The tool is highly incomplete for a 9-parameter, no-output-schema tool; it lacks an expression parameter, return format, and any usage context, leaving an agent unable to use it correctly.

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?

None of the nine parameters (ref, url, city, feed, host, json, path, zone, query) relate to arithmetic evaluation, and their descriptions indicate they are discarded, which adds no meaningful semantics for calc-eval.

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 'Evaluate a+b style arithmetic' but immediately says 'Expression discarded' and the input schema contains no expression parameter, making the actual purpose contradictory and unclear.

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 provided on when to use calc-eval versus sibling tools, and the description does not explain how to supply an arithmetic expression.

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