add

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

No annotations are provided, so the description must carry the burden. The description correctly implies it performs addition and returns a result, but does not mention any edge cases (e.g., overflow) or whether the tool is idempotent. A score of 3 is appropriate given the simplicity.

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 very short and to the point, which is appropriate for a simple tool. It could be considered slightly too brief, but as a single sentence it earns its place.

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?

Given the tool's simplicity and the presence of an output schema, the description is adequate but not complete. It does not mention whether the addition uses integer or floating-point arithmetic, or any constraints. A more complete description might include 'Returns the sum of two integers.'

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 provides 0% description coverage, meaning the description does not elaborate on parameters beyond what is in the schema. The description simply mentions 'two numbers', which adds no extra meaning over the schema field names 'a' and 'b'. Baseline 3 applies because schema coverage is low but the tool is extremely simple.

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' clearly states the verb (add) and resource (numbers), but it is very brief and does not distinguish from any potential siblings or provide additional context.

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?

No guidance is given on when to use this tool versus alternatives, nor any prerequisites or limitations. For a trivial arithmetic tool this may be acceptable, but the scoring criteria requires explicit guidance.

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