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

No annotations are provided, so the description carries the full behavioral burden. It implies a pure calculation but does not state that it is side-effect-free, deterministic, or read-only, and it does not explain how input should be formatted (schema says string, description says array) or what happens with missing or malformed values.

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 short sentences, front-loaded with the definition. Minor redundancy in 'Midhinge: Calculate the midhinge' but no wasted explanation.

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 statistical calculation, the core operation is described, but with no output schema or annotations the definition leaves input format and return behavior underspecified. It is adequate but has clear gaps.

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 description coverage is 100%, so the baseline is 3. The description adds 'values array', but this conflicts with the schema's type of string and does not clarify delimiter, parsing, or expected numeric format.

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 'midhinge', including a formula definition. Clear enough to identify the operation, but does not differentiate from nearby statistical siblings such as x402-quartile, x402-iqr, or x402-midrange.

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?

Provides no when-to-use guidance or alternatives. The only usage instruction is 'Provide values array', which is an input instruction, not a routing guideline for choosing this tool over sibling statistical tools.

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