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

With no annotations provided, the description must carry the full burden of behavioral disclosure. However, it provides zero information about how the tool behaves, what it returns, or any side effects, relying entirely on the name.

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 and redundant, repeating the tool name without adding any information. It is not front-loaded with useful content and fails to 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?

Given the tool has two parameters and no output schema, the description is completely inadequate. It lacks any explanation of inputs, outputs, or behavior, making it impossible for an agent to use the tool correctly without reverse-engineering from the schema.

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 schema description coverage is 100%, so the parameters 'revenue' and 'operatingIncome' are already documented in the schema. The description adds no additional meaning, which meets the baseline of 3 when schema coverage is high.

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 "Operating Margin: Operating Margin" merely restates the tool name in a tautological format. It does not clarify what specific operation is performed (calculation, lookup, etc.) or distinguish it from siblings like x402-gross-margin or x402-profit-margin.

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 on when or why to use this tool. It does not mention any alternatives or contexts for usage, leaving the agent with no information to select this over other margin-related tools.

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