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

With no annotations, the description carries the burden of behavior, and it explains the key return behavior: middle value, or average of two middles for even counts. It does not discuss sorting, empty arrays, or non-numeric handling, but for a simple statistical utility the core behavioral contract is disclosed.

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 only two short sentences and is front-loaded with the core purpose. Every sentence adds useful information, and there is no filler.

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 helper with no output schema and no annotations, the description states purpose and return behavior clearly. The main gap is the string-typed parameter: the description says 'numeric array' but does not specify how the values must be formatted within the string, which an agent may need to invoke correctly.

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%, so the schema already documents the single 'numbers' parameter. The description adds that the input should be a numeric array, which is useful, but it does not clarify the string format expected by the schema (e.g., JSON array, comma-separated). This is adequate but not additive beyond the baseline.

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 identifies the tool as calculating the median of a numeric array, using a specific verb and resource. It distinguishes the operation by explaining the middle-value behavior and the even-count averaging rule, which separates it from median-related siblings like x402-median-absolute-deviation or x402-median-filter.

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?

Usage is implied: call this tool when you need the median of numeric values. However, there is no explicit guidance about when not to use it or which sibling tool to prefer, such as x402-median-absolute-deviation or x402-weighted-median.

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