add

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

The annotations already carry the readOnly, idempotent, and non-destructive behavior, so the description does not need to repeat that. It adds the finite-number constraint, but it does not disclose edge-case behavior such as overflow, precision limits, or handling of invalid non-finite inputs.

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 sentence that front-loads the operation and immediately clarifies the operands with the formula. Every word earns its place, with no filler or 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-parameter arithmetic tool, the description is nearly complete: the operation, operand roles, and safety profile are all clear, and the output schema covers the return value. A small remaining gap is explicit guidance on non-finite or invalid inputs, though the word 'finite' partially addresses that.

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?

With zero schema description coverage, the schema's titles 'A' and 'B' carry no meaning on their own. The description gives both parameters semantic context through 'a + b' and the finite-number interpretation, but it provides no per-parameter constraints beyond that.

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 states a specific operation (add) and a specific resource (two finite numbers), and reinforces it with the formula 'a + b'. This clearly distinguishes it from the sibling tools subtract, multiply, and divide.

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 makes the applicable context clear: use this tool when two finite numbers need to be summed. It does not explicitly name alternatives or exclusions, but the operation name and formula make the choice obvious against the listed siblings.

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