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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds genuine value beyond those annotations by stating the calculation formula, the use of absolute value, and that the result is magnitude only with no base direction or prescription recommendation. It stops short of clarifying the mm-to-cm unit conversion, but the core behavioral profile is transparent.

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 entire description is a single tight sentence that front-loads the central formula and immediately follows with the return limitation. Every phrase adds either formula context or usage caution; there is no filler.

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 three-parameter calculator the description covers the formula and the nature of the return value, which is a reasonable baseline. However, without an output schema it leaves the output unit unstated, fails to mention the language parameter, and does not resolve the displacement unit mismatch, so an agent could still invoke or interpret the result incorrectly.

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 0%, so the description carries the full burden for parameters. It references meridionalPower and displacement through the formula and clarifies absolute value, but it omits the language parameter entirely and refers to 'displacement in cm' while the actual property is displacementMm, which is potentially misleading. Ranges, units, and conversions are not explained.

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 identifies the operation as a Prentice approximation using absolute meridional power times displacement, and it explains that the return is magnitude only with no base direction or prescription recommendation. It does not use an explicit action verb like 'calculates', but the formula and return scope make the purpose unambiguous. It is distinct enough from the sibling calculation tools, though it does not name a specific sibling.

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 word 'Educational' and the explicit 'no prescription recommendation' imply that this is for learning contexts rather than clinical decision-making. However, there is no positive guidance on when to choose this tool over the siblings, nor any named alternatives or exclusions beyond the recommendation caveat.

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