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

Annotations already declare this a safe, idempotent, non-destructive read. The description adds real behavioral context beyond that: the computation performed and the fact that the result is a comparison against the hotend limit plus a maximum safe speed, which is effectively return-value behavior for a tool with no output schema.

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 compact sentences, front-loaded with the purpose and formula, with the accepted preset list trailing usefully. The preset enumeration with an ellipsis is slightly loose but not wasteful.

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 5-parameter tool with no output schema and low schema coverage, the description covers purpose and computation but not validation rules, units, or the precise shape of the result (single flow number vs. a max-speed recommendation). Adequate but with clear gaps.

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 only 20% (just the hotend enum), so the description must compensate. It does clarify that line width and layer height feed the flow formula and that max_volumetric_flow_mm3_s is an alternative to a preset, but it leaves units and the interaction of the two mutually exclusive flow inputs (hotend vs explicit max flow) unexplained.

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 states a specific verb and resource plus the exact formula being evaluated: volumetric flow (mm³/s) = layer height × line width × speed, checked against the hotend limit. It is clearly distinguishable from siblings like calculate_filament_usage or calculate_print_cost.

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 framing 'Check whether a hotend can keep up' implies the use case, and it notes the two input modes (hotend preset name or explicit max flow). However, it gives no explicit when/when-not guidance or named alternatives among the calculator siblings, so usage must be inferred.

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