subtract

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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond annotations by clarifying operand order (non-commutative behavior) and the constraint that both operands must be finite numbers.

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 efficient sentence that front-loads the formula and then adds the key constraint. Every word earns its place with no redundancy.

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 two-operand arithmetic tool with comprehensive annotations and an output schema, the description covers the essential semantic and constraint information. Nothing critical is missing for an agent to invoke 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?

Since the schema provides no parameter descriptions, the description carries the burden of explaining 'a' and 'b'. It does so via the formula, making clear that 'a' is the minuend and 'b' is the subtrahend, and adds the finite-number requirement. This is strong compensation for 0% schema 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 operation with a specific formula, 'Subtract b from a: a - b', which precisely defines the tool's behavior. It distinguishes itself from siblings like add, multiply, and divide by naming the exact arithmetic operation and operand order.

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 the tool is for subtraction but does not explicitly state when to use it versus the sibling tools add, multiply, or divide. For a simple arithmetic operation this is minimally sufficient, yet there is no explicit usage context or exclusion.

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