stats

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

With no annotations provided, the description carries the full burden. It specifies the output statistics, including a note on population vs. sample stddev, which is useful. However, it does not disclose behavior for edge cases (e.g., empty list, non-numeric input, multiple modes) or define terms like MAD. This is a moderate disclosure, not comprehensive.

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 a single sentence that immediately states the core purpose and then lists all supported statistics. It is dense but every word adds value, with no repetition or filler. The front-loaded purpose ensures quick comprehension.

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 tool is simple (one param, no output schema, no annotations). The description lists the full set of return statistics, giving a clear idea of the output. However, it does miss edge-case behavior or usage nuances (e.g., how mode is determined, string parsing details). For a pure calculator, this is nearly complete, but not fully.

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 schema has only one parameter 'numbers', and the description does not add any meaning beyond saying it's a list of numbers. The schema itself includes a small description for the string variant ('Comma- or whitespace-separated numbers'), but the context signal indicates 0% schema description coverage overall. The tool description fails to compensate by explaining acceptable formats, types, or examples, leaving an agent to rely solely on 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's function with a specific verb ('Descriptive statistics') and resource ('a list of numbers'), followed by an exhaustive list of outputs (count, sum, mean, median, etc.). This unambiguously distinguishes it from sibling tools like count_lines or base64_encode, which serve different purposes.

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 purpose is clear, implying when to use the tool (whenever numeric statistical summaries are needed), but there is no explicit guidance on when not to use it or mention of alternative tools. No exclusions or alternative references are provided, so the usage context is only implied.

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