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 clearly states what the operation is and what it returns. For a trivial pure arithmetic tool, this is sufficient transparent behavior and leaves no hidden side effects unaddressed.

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 contains exactly the necessary information. It is front-loaded with the operation and immediately states the output.

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-number arithmetic tool, the description is complete. It specifies inputs, operation, output, and the tool has no complex side effects, error cases, or advanced options that require explanation.

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 a and b as required numbers but no per-property descriptions. The description says 'two numbers,' which conveys basic semantics, but it does not add meaningful detail beyond the schema's parameter names and types. This is adequate but minimal.

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 (adding two numbers) and the output (sum). It reads as a pure, unambiguous definition of the tool and is clearly distinguishable from the sibling tools echo and server_time.

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 explicit guidance is given about when to use this tool versus its siblings. Usage is implied by the operation itself, but there is no conditional guidance, exclusions, or mention of alternatives.

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