util_average

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

The description provides the formula, which adds transparency beyond the basic schema. However, it does not mention behavior with edge cases like NaN or infinity, despite no annotations covering such details.

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 concise with two sentences, each adding value: purpose and formula. No wasted 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 utility with one parameter and schema coverage at 100%, the description is complete. It explains the calculation clearly, and no output schema is needed.

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 input schema already describes the parameter with a Chinese comment indicating 'at least 1 element'. The description adds the formula but no extra semantic meaning beyond 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 computes the arithmetic mean of an array, with the formula 'sum(values) / length'. It distinguishes from sibling statistical tools like util_median and util_stddev.

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 alternatives such as median or min/max. The description lacks contextual usage advice.

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