calculator

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

The description mentions 'Safely evaluates' implying sandboxed execution, and lists supported functions, but does not disclose limitations like expression length, timeout, error handling, or side effects. With no annotations, more detail would be beneficial.

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 concise with two paragraphs, first stating the core purpose and second listing capabilities. It is front-loaded with the key verb 'evaluates' and resource 'expression string', though the list of functions could be shortened.

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?

The description covers the expression syntax and variable usage, but lacks information about the return value format (e.g., numeric result) and any potential errors. Given the absence of an output schema, this omission reduces completeness.

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?

With 0% schema description coverage, the description adds significant meaning: explains that 'expression' uses Python syntax, and 'variables' can include lists for time series data. This compensates well for the lack of parameter descriptions in the schema.

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 evaluates mathematical/statistical expressions using Python syntax, lists supported operations and functions, and distinguishes it from sibling tools that are financial or data-oriented.

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 provides clear context for when to use the tool (evaluating math/stat expressions) but does not explicitly state when not to use it or suggest alternatives for more specific calculations, such as financial formulas.

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