Add two numbers

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

With no annotations provided, the description carries the full burden of behavior. It states that the tool adds two numbers and returns the result, which is transparent and implies a pure function with no side effects. It does not mention error handling or edge cases, but for a simple addition, this is sufficient.

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, clear sentence that directly conveys the tool's purpose without any extraneous information. It is well-structured and easy to parse.

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 specifies the inputs (two numbers), the action (adds), and the output (returns the result). No additional context is needed 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?

The schema fully documents the parameters (a and b, both numbers, required), and the description simply restates 'two numbers' without adding extra meaning about ordering, constraints, or special values. Since schema coverage is 100%, the baseline of 3 applies.

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 (adds) and the resource (two numbers), and the result is implied. It distinguishes from sibling tools like multiply, get-weather, and save-note by specifying the exact arithmetic operation.

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 does not explicitly mention when to use this tool versus alternatives, but the context of sibling tools (multiply, weather, note) makes it implicitly clear that this is for addition. No exclusions or edge cases are noted.

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