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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false. The description adds no behavioral detail beyond 'client and server side', which is ambiguous and not actionable; it does not disclose operations or constraints.

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?

It is short, but the only content beyond the tool name is vendor/'client and server side' fluff. It is under-specified rather than concise, with no useful structure or front-loaded operation details.

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 three-required-parameter calculator with an enum operation and no output schema, the description omits what is calculated, which operation to choose, and how inputs map to results. It is not complete enough to call 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?

Schema description coverage is 0% for all three required parameters (a, b, operation), and the description does not mention any parameter. It fails to explain the operation enum values percentageOf, whatIsPercentOf, or percentChange, or how a and b are used.

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 says only 'Percentage calculator client and server side from freedailypro', which essentially restates the tool name/title and vendor. It does not state a specific operation or distinguish it from sibling calculators like calculate_discount or calculate_tip.

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 when-to-use guidance, no alternatives, no exclusions. The many sibling calculator tools make routing ambiguous, and the description does not help an agent select this tool over the others.

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