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

No annotations exist, and the description discloses no behavior beyond the name. It does not state whether the operation mutates state, requires any authentication, handles edge cases, or returns a vector, scalar, or error. The description is entirely uninformative.

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 extremely short, but this is under-specification rather than concise effectiveness. The single sentence 'Vector Cross: Vector Cross' repeats the name and adds no information, so it fails the requirement that every sentence earn its place.

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 four ambiguous string parameters, no output schema, no annotations, and many similar math/vector siblings, this description is completely inadequate. The agent cannot determine parameter format, dimensionality, expected output, or even confirm this is a mathematical cross product.

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 per the baseline the description need not add parameter detail. However, the existing parameter descriptions ('A to process', 'B to process', 'V1 to process', 'V2 to process') are semantically empty stubs, so the tool's parameters remain effectively unexplained.

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 is 'Vector Cross: Vector Cross', which simply restates the tool name without any verb, resource, or operation detail. It gives no indication of what inputs are involved or what output is produced, and it fails to distinguish this tool from siblings like x402-cross-product2d or x402-vector-dot.

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 guidance about when to use this tool versus alternatives. The description does not mention related tools, prerequisites, or contexts, leaving the agent to guess whether this handles 2D/3D vectors or how it differs from x402-cross-product2d.

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