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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it reveals nothing. It does not say whether the tool generates, mutates, validates, or transforms data, whether it requires credentials, or what side effects or return behavior to expect.

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 short but not concise—it is redundant and empty. It spends its only sentence repeating the tool name instead of conveying useful information. Under-specification is not the same as conciseness; this is closer to the 'Process' calibration example.

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?

A tool named 'query-string-build' presumably constructs a query string, but the empty schema and vacuous description leave the agent with no idea what inputs to provide or what the tool returns. It is completely inadequate even for a zero-parameter tool, and no relation to siblings or expected output is described.

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 input schema has zero parameters, and the rule establishes a baseline of 4 for that case. Since there are no parameters to document, the description does not need to add parameter-level meaning. It adds nothing, but the baseline stands because there is no schema gap to compensate for.

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 'Query String Build: Query String Build' is a pure tautology that merely restates the tool name. It does not state a specific verb, resource, or behavior beyond what is already visible in the name, nor does it differentiate the tool from its sibling x402-query-string-parse.

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. With a closely related sibling called x402-query-string-parse, the agent gets no hint about which direction (build vs parse) fits the task. No context, exclusions, or examples are provided.

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