List available functions

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

Beyond the readOnlyHint annotation, the description adds critical behavioral context: that all functions are available on all 4 engines but results may diverge at poles, branch cuts, or ties, and that this divergence is intentional backend behavior. This significantly helps the agent understand potential variability.

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: two sentences that front-load the core purpose and return structure, followed by a clear statement of usage and a critical behavioral note. No unnecessary words.

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 list tool with one optional parameter and no output schema, the description fully covers what the tool does, what it returns (name, arity, category, description), and a key behavioral nuance. The agent can confidently use or avoid this tool based on this description.

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?

Schema coverage is 100% with the single optional parameter 'category' described. The description adds value by enumerating the exact allowable categories ('algebraic, trigonometric, hyperbolic, exponential, special, rounding, introspection'), which the schema only gives examples for. This provides more precise guidance.

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 specifies the tool lists mathematical functions, names the API, and states the return fields (name, arity, category, description). It distinguishes itself from the sibling tool 'evaluate' by indicating its purpose is to discover functions for that tool.

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 explicitly tells when to use this tool ('to discover what functions you can pass to the evaluate tool') and notes optional filtering by category. It does not explicitly state when not to use it, but given the only sibling is 'evaluate', the guidance is sufficient.

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