modulus

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

Beyond annotations, the description discloses that b must not be zero and that DivisionByZeroError is raised if violated, which is critical behavioral context. It also specifies the return value. There is no contradiction with the readOnly and idempotent 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 uses a clear docstring structure with Args, Returns, and Raises sections, making it easy to parse. It is appropriately sized, with each section earning its place, though slightly more verbose than the absolute minimum.

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 simple arithmetic operation, the description is complete: it covers the operation, both parameters with roles and constraints, the return value, and the error condition. With an output schema present, no additional return structure details are needed.

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?

The schema only provides types (number) and titles (A, B), but the description adds semantic meaning by labeling a as the dividend and b as the divisor, plus the constraint that b must not be zero. This fully compensates for the 0% schema description coverage.

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 clearly states the tool computes the remainder when dividing a by b, precisely defining the modulus operation. This distinguishes it from sibling tools like divide, which computes the quotient, and other arithmetic operations.

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 description implies use cases for remainder calculations but does not explicitly state when to prefer this tool over alternatives like divide. It lacks clear 'when to use' or 'when not to use' guidance, though the mathematical definition is self-evident.

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