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

No annotations are provided, so the description carries the full behavioral burden, yet it discloses nothing: no indication of whether the percent is a whole number (10) or a fraction (0.1), no rounding behavior, no error handling for non-numeric input, and no return shape. For a tool with zero structured behavioral coverage this is a total gap.

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?

It is short, but the length is achieved by duplication rather than efficiency: the name is simply printed twice after a colon. Nothing is front-loaded because there is no substantive content to front-load.

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 arithmetic tool with no annotations and no output schema, the description still omits the two things an agent actually needs: the expected units of "percent" and what the returned value represents. The schema covers the parameters, but the invocation semantics remain unspecified.

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 both parameters are documented in the schema, and the rubric sets a baseline of 3 when the schema does the heavy lifting. However, the schema's own text is thin ("Value to process", "Percent to process"), and the description adds no units, format, or range clarification to compensate.

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 a pure restatement: "Increase By Percent: Increase By Percent" repeats the tool name twice without stating what resource is processed or what the output is. It is a textbook tautology, and it does not distinguish this tool from close siblings such as x402-decrease-by-percent, x402-percent-change-array, or x402-percentage-change.

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 statement of when to use this tool, when not to, or which sibling to prefer. The agent must infer from the name alone that this computes a single value increased by a percentage rather than, say, a percent-change over an array.

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