Add

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

Without annotations, the description carries full burden. It accurately describes a pure function with no side effects. However, it does not mention that the result is a number or potential overflow, but the schema implies numeric return.

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 of four words, perfectly concise with no wasted words. It front-loads the action and object.

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 tool with two clear number parameters and no output schema, the description is complete. It covers purpose and behavior adequately.

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?

Schema coverage is 100% with descriptions 'first addend' and 'second addend'. The description adds no additional meaning beyond these, so a baseline 3 is appropriate.

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 (two numbers), leaving no ambiguity about the tool's purpose. It is specific and need not differentiate from siblings as none exist.

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 doesn't provide explicit when-to-use or alternative guidance, but given the tool's simplicity and absence of siblings, the usage context is obvious. It misses an opportunity to mention that this is for simple numeric addition only.

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