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

With no annotations, the description carries the full burden; it usefully discloses the return semantics (sequence runs until 1) and that input must be a positive integer, which implies a deterministic read-only computation. It does not state what happens for n <= 0, whether the output is an array or string, or any limits, leaving meaningful 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 short sentences, front-loaded with the action and followed by the input instruction and return behavior. No filler, though the 'Collatz:' label prefix is slightly redundant with the name.

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 deterministic math tool with no output schema, the description covers input and output shape adequately. It falls short on edge-case behavior (non-positive n), the exact return format, and the role of the second schema parameter.

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 baseline is 3, and the schema's own descriptions ('N to process', 'Value to process') are nearly meaningless. The description adds value by naming n as the input to provide, implicitly deprioritizing the confusing 'value' parameter, but it never explains what 'value' is for, leaving the two-parameter ambiguity only half resolved.

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 and resource ('Generate the Collatz sequence for a positive integer n') and describes the output ('sequence until it reaches 1'). However, it does not distinguish itself from the near-identical sibling x402-collatz-sequence, so an agent cannot tell which to pick 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?

'Provide n' gives minimal input guidance but there is no when-to-use context, no mention of when not to use it, and no routing to alternatives such as x402-collatz-sequence, x402-hailstone-length, or x402-hailstone-max.

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