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

With no annotations available, the description carries the full burden of behavioral disclosure and fails completely. It reveals nothing about whether the sort mutates input, what data types it accepts, how it handles edge cases, what it returns, or its algorithmic behavior. The description adds no behavioral context whatsoever.

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?

This is under-specification, not conciseness. 'Merge Sort: Merge Sort' is two repeated words that deliver zero information while occupying minimal space. True conciseness requires every word to earn its place; these words are wasted on repetition.

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 tool with no annotations, no output schema, no parameters, and a tautological description, nothing an agent needs to call it correctly is present. The agent cannot know what input to provide, what output to expect, or how this differs from the dozens of sibling sorting tools (bubble-sort, insertion-sort, selection-sort, quick-sort, sort-lines, sort-numbers, sort-strings). This is completely inadequate.

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 tool has zero parameters and the schema documents them fully at 100% coverage, so the baseline of 4 applies per the rubric. There are no parameter semantics for the description to add. However, the empty schema combined with the tautological description leaves an agent wondering how input data is even provided to a merge-sort tool, which is a real gap, but it falls outside parameter semantics strictly.

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 'Merge Sort: Merge Sort' is a pure tautology that merely restates the tool name with a colon separator. It contains no verb, no resource, no behavior, and no indication of what the tool actually does. An agent cannot distinguish this from sibling sorting tools like x402-bubble-sort, x402-quick-sort, or x402-sort-numbers.

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 description provides zero guidance on when to use this tool versus alternatives. It never mentions merge sort's O(n log n) complexity, stability characteristics, or suitability for large datasets. No sibling tool is named, so an agent has no basis for choosing between this and the numerous other x402-*-sort tools.

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