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

With no annotations, the description carries the full behavioral burden, and it does disclose the exact computation (average of min and max), which is the core behavior. However, it says nothing about error handling for empty/single-element input, output format, or whether the input is comma-separated — reasonable gaps for a pure deterministic math function, but still gaps.

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?

Two sentences, front-loaded with the definition and formula, followed by the single input instruction. No filler and nothing misplaced.

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 one-parameter, no-annotation, no-output-schema math utility, the description supplies the definition, formula, and input pointer. The main omission is the expected format of the values string, which matters given the schema's string type.

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% and there is only one parameter, so the baseline is 3. The description adds a mild hint by calling it a 'values array,' but the schema types it as a string, leaving the actual delimiter/format ambiguous rather than clarified.

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?

States a specific verb (calculate) and resource (midrange) and even supplies the formula, which implicitly distinguishes it from siblings like median, mode, range, and midhinge. It does not name any sibling explicitly, so it falls short of a 5, but an agent can identify the operation from the description alone.

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?

There is no when-to-use guidance, no conditions selecting this over the many other statistics siblings (mean-of, median, midhinge, range), and no exclusions. The only directive, 'Provide values array,' is parameter instruction rather than usage context.

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