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

With no annotations, the description carries the full burden of explaining behavior. It discloses the formula but says nothing about output format, units, edge cases like zero area, or how inputs are actually supplied. The instruction to 'provide force and area values' conflicts with the empty input schema, which is misleading for the agent.

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 very short and front-loaded, communicating the formula and required inputs quickly. Minor redundancy exists: 'Pressure:' and 'Calculate pressure' both restate the tool name, but the overall length is appropriate.

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 no output schema and no annotations, the description omits essential details: return value, units, input mechanism, and behavior on invalid inputs. Given the empty input schema, the description leaves the agent unable to correctly construct an invocation even though the core formula is clear.

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 description names force and area as the relevant inputs, adding conceptual meaning beyond the empty schema. However, the schema declares zero properties, so the agent has no structured way to pass these values; the description promises inputs the tool contract does not support.

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 clearly states the tool's purpose: calculating pressure as force divided by area, with an explicit formula and required conceptual inputs. It is specific enough to avoid confusion with sibling tools like x402-pressure-unit or x402-ideal-gas-pressure, though it does not name them.

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?

The description implies direct calculation from force and area values, but it provides no guidance on when to use this tool versus alternatives such as x402-ideal-gas-pressure, x402-force, or x402-pressure-unit. No exclusions, prerequisites, or context are given.

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