percentage_calc

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It says nothing about side effects, precision, rounding, error conditions, or return format beyond the calculation itself, leaving key behavioral traits unspecified.

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 a single, front-loaded sentence that states the purpose and lists the operation modes with zero wasted words. It is appropriately sized for a simple calculator tool.

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 low-complexity 3-parameter calculator with 100% schema coverage and no output schema, the description covers the essential purpose and operation names. However, it does not explain the roles of 'a' and 'b' for each operation (e.g., which is the base vs. the percentage), which is a meaningful gap for correct invocation.

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 100%, so the schema already documents all three parameters (including the operation values). The description repeats the operation list but adds no new meaning about how 'a' and 'b' map to each operation, so the baseline of 3 is appropriate.

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 and resource ('Perform percentage calculations') and enumerates the supported operations, making it clear what the tool computes. It does not explicitly differentiate itself from sibling math tools like percentile_calc or proportion_solve, but the purpose is unambiguous.

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?

The operation list implies when to use the tool (for of, change, increase, decrease, or is_what_percent calculations), giving clear implied usage. However, there is no explicit when-to-use guidance, no exclusions, and no routing to alternatives among the many sibling calculators.

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