add

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

No annotations are provided, so the description carries the full burden. It accurately states the core operation but does not explicitly mention the return value (the sum) or any error conditions. For a pure arithmetic operation this is a minor gap, but a strictly higher score would require more explicit behavioral disclosure.

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, tightly worded sentence that wastes no words and front-loads the operation. It is concise and well-structured for a simple 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 two-number arithmetic tool, the description is largely complete: it specifies the operation and the schema defines required inputs. There is no output schema or annotations, but the expected result (the sum) is universally implied. A slightly higher score would require explicit mention of return type or edge cases, which are low-risk here.

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?

Input schema covers both parameters fully (100% coverage) with descriptions for 'a' and 'b'. The tool description adds no parameter-level semantic detail beyond indicating the operation is addition, which is expected. Baseline 3 is appropriate when schema already documents parameters.

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 'Add two numbers together' uses a specific verb (add) and resource (two numbers), clearly distinguishing it from sibling arithmetic tools like subtract, multiply, and divide. An agent can immediately understand what this tool does and how it differs from alternatives.

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 clearly implies the context of use: whenever addition of two numbers is needed. Though it doesn't explicitly enumerate when not to use it versus alternatives, the semantic clarity of 'add' combined with the sibling names makes the choice unambiguous.

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