calculate

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

With no annotations, the description carries the full burden of disclosing behavior, but it only lists the operations without mentioning edge cases such as division by zero, overflow, or error handling. The pure, deterministic nature of arithmetic is implied rather than explicitly stated.

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 compact sentence that front-loads the tool's purpose and enumerates the operations with no filler. It is appropriately sized and every word contributes to understanding the tool.

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 calculator with three required, fully documented parameters and an obvious numeric return value, the description is mostly complete. It omits edge-case behavior like division by zero, but the schema's thorough parameter documentation compensates for this minor gap.

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 full descriptions for all three parameters, including an enum for the operation, so the schema description coverage is 100%. The description simply restates the same operations in prose without adding any semantic detail beyond what the schema already provides.

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 clearly states the tool's function with a specific verb ('Performs') and resource ('arithmetic operations'), and enumerates the exact operations it supports. It is obviously distinct from the sibling tools (greeting, weather, notes), leaving no ambiguity about its purpose.

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 gives no explicit guidance on when to use this tool versus alternatives, and no exclusions are mentioned. While the sibling tools are unrelated and the use case is self-evident, the description still does not provide any selection context or conditions.

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