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

No annotations are present, and the description only vaguely mentions 'Expression discarded' without clarifying side effects, output behavior, or error handling. The statement is inconsistent with the provided parameters, so it does not meaningfully disclose behavior.

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 brief but not effectively front-loaded; it introduces an arithmetic purpose that is contradicted by the schema. Every word should add clarity, but here the phrase 'Expression discarded' adds confusion rather than value.

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?

With nine parameters and no output schema, the description is grossly incomplete. It neither explains what the function returns, how parameters are used, nor why they are diverse. The tool's behavior cannot be inferred from the description alone.

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?

Each parameter in the schema has a description, but the tool description does not explain how any of these parameters relate to arithmetic evaluation. The descriptions cover individual parameters but fail to connect them to the tool's stated purpose, leaving the parameter roles unclear.

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?

Description states 'Evaluate a+b style arithmetic' clearly, but the input schema contains parameters like url, city, feed, and zone that are unrelated to arithmetic. This mismatch makes the actual purpose ambiguous and confusing.

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 guidance is provided on when to use this tool versus any of the sibling tools. There is no mention of alternatives, context, or prerequisites.

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