calculate_fueling_plan

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

Annotations already establish that this is read-only and non-destructive, so the description doesn't need to repeat safety behavior. It does add useful context by clarifying this is an estimate rather than a medical prescription, and by noting the optional input sources. However, it doesn't describe the shape of the result or any assumptions/defaults when optional inputs are omitted.

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?

Two sentences deliver the core purpose, input variables, optionality, and a necessary disclaimer with no filler. The main action is front-loaded, making the tool's function immediately scannable.

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 planning calculator with no output schema, the description is nearly complete: it states what is calculated, the inputs required, and the estimate caveat. It could be slightly more explicit about the returned ranges or how optional inputs affect the result, but it gives an agent enough to know when and how to invoke it.

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 burden of explaining parameters. It names all five inputs in plain language and correctly labels sweat/sodium as optional, which is useful. But it doesn't add significant meaning beyond the schema's self-descriptive property names, units, and required list, nor does it explain the intensity enum values or what 'practical ranges' means for each parameter.

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 uses a specific verb ('calculate') with a clear resource ('practical carbohydrate, fluid and sodium ranges for an endurance session'). It identifies the core domain and differentiates itself from the workout/calendar/analysis siblings by describing a unique fueling-planning task.

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 sets clear context: it is for endurance-session planning, uses duration, intensity, temperature, and optional sweat/sodium inputs, and explicitly frames the result as a planning estimate rather than medical advice. It doesn't name alternatives, but no sibling tool provides a similar fueling calculation, so no exclusion is needed.

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