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 neither explains what the tool returns, what side effects occur, nor how the many input parameters are handled beyond vague 'discarded' comments in the schema. The single clause 'Expression discarded' is cryptic and does not convey 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 extremely short, which on its own could be good, but it is not front-loaded with useful information. The key phrase 'a+b style arithmetic' does not match the schema, and 'Expression discarded' is confusing. Being brief is not valuable if it fails to communicate.

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?

This tool has 9 parameters, no required fields, no output schema, and no annotations. The description does not explain what the tool does with these parameters, what the output would be, or how it connects to the tool name. It is completely inadequate for an agent to invoke 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?

Although schema coverage is 100% and each parameter has a description, the tool description adds no value per parameter. Worse, it introduces an arithmetic concept that does not map to any schema parameter, making it harder for an agent to understand how to fill in the fields.

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 says 'Evaluate a+b style arithmetic' which names a clear verb and resource, but the input schema has no parameter for an expression (no 'a' or 'b'). This makes the purpose ambiguous and potentially misleading. The phrase 'Expression discarded' adds confusion rather than clarity about what the tool does.

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 given on when to use this tool versus any of the 26 siblings. The description does not hint at use cases, prerequisites, or exclusions. An agent has no way to choose this tool correctly.

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