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

With no annotations provided, the description must carry the full behavioral burden. It only says 'Expression discarded' without explaining side effects, return values, or constraints. The tool's actual behavior (likely a shape or format check) is entirely undisclosed.

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 extremely short, but this is under-specification rather than effective conciseness. It omits critical context and does not earn its place by clarifying the tool's purpose or usage.

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 tool with 9 parameters, no output schema, and no annotations, the description is wholly inadequate. It does not explain what the tool does with the parameters, what it returns, or how it fits into the broader toolset, leaving an agent with no basis to call it correctly.

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 covers all 9 parameters with individual descriptions, but the tool description adds no clarification on how they relate to the claimed arithmetic operation. The description is actively confusing, providing zero semantic value beyond the schema and failing to bridge the mismatch.

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 claims the tool evaluates arithmetic expressions, but the input schema contains parameters for URLs, cities, timezones, and other unrelated data. This mismatch makes the actual purpose unclear and misleading; an agent cannot infer what the tool really does from the description.

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?

There is no guidance on when to use this tool versus its many siblings. No context is given about which scenarios call for this tool, and the arithmetic description does not align with any of the parameter purposes.

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