add

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

With no annotations, the description carries the full burden of behavioral disclosure. It accurately describes a pure, side-effect-free operation with no hidden state changes, permissions, or side effects. The behavior is fully captured by the statement 'Adds two numbers together', which is adequate for this trivial function.

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 six-word sentence that is front-loaded and to the point. Every word earns its place, and there is no redundancy or filler.

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 extreme simplicity of the tool (two numeric parameters, no side effects, no output schema), the description is fully complete. It states the operation, and the return value (the sum) is logically implied. Additional context would be unnecessary and would not improve usability.

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 input schema already provides 100% coverage with descriptions for both parameters ('The first number' and 'The second number'). The description reinforces that the operation is addition but adds no additional meaning beyond what the schema already specifies, so it meets the baseline for high schema coverage.

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 'Adds two numbers together' uses a specific verb and resource, clearly stating the arithmetic operation. It immediately distinguishes itself from sibling tools like echo and get_timestamp, which serve entirely different purposes.

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 context is unambiguous: this tool is for adding two numeric values. While no explicit alternatives or exclusion conditions are mentioned, the simplicity and clarity of the purpose make the appropriate usage obvious, and the sibling tools are disjoint in functionality.

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