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

No annotations are provided, so the description must carry the full behavioral burden. It only says 'Expression discarded,' which is vague and unconnected to any parameter. It does not disclose side effects, auth requirements, rate limits, return format, or any other behavior. This is grossly inadequate for a tool with no annotation safety hints.

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 short (one sentence), but it is under-specified rather than concise. It lacks essential information about parameter mapping and purpose, so brevity here is a defect, not a virtue. Front-loading is irrelevant when the content is misleading.

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?

With 9 parameters, no output schema, and no annotations, the description is severely incomplete. It does not explain return values, how parameters relate to the operation, or any usage context. An agent has essentially no useful information to make a correct call. This is far below the minimum viable for a tool of this complexity.

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 the baseline is 3, but the description adds no parameter meaning and actively confuses it. The description says 'arithmetic' while schema params are about URLs, cities, JSON, paths, etc. It does not clarify which parameter holds the arithmetic expression, so an agent cannot correctly invoke the tool from the description alone.

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 verb ('Evaluate') and resource ('a+b style arithmetic'), but it does not map to any of the 9 schema parameters. No parameter is named as the expression, and the listed params (ref, url, city, etc.) seem unrelated to arithmetic. It also fails to distinguish this tool from its 27 siblings, which are mostly fetch/validation tools.

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 this tool versus alternatives. No mention of scenarios, prerequisites, or exclusions. The description gives no context that would help an agent decide to call calc-eval over, say, fetch-status or validate-json.

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