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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is fully covered for a pure computation. The description adds domain context (the "magic number" concept, default kinematics, and output "filtered to what suits the nozzle") but no return format or error behavior.

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, front-loaded with the verb and resource followed by a parenthetical default example. Tight and purposeful, with 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 six-parameter calculator with no output schema and no parameter descriptions in the schema, the description is adequate but not complete: it omits the max_layer_height_mm parameter and says nothing about the shape of the returned layer-height list, which the agent would need to use the result.

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 must carry parameter meaning; it covers step angle, microstepping, and lead-screw pitch/starts and even echoes the default values (1.8°, 1/16, T8 2 mm × 4 starts). However, nozzle_diameter_mm is only hinted at ("filtered to what suits the nozzle") and max_layer_height_mm is never mentioned, leaving one of six parameters undocumented.

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 gives a specific verb ("Compute") and resource ("Z-axis magic number layer heights for a printer") and enumerates the driving inputs. It is clearly distinguishable from the calculate_filament_usage / print_cost / volumetric_flow siblings by resource, though it never names an alternative explicitly.

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?

Usage is implied by the domain (feed in printer kinematics, get layer heights) and the default set signals a common Ender/Prusa scenario, but there is no explicit when-to-use or when-not-to-use guidance relative to the sibling calculators. Meets the minimum-viable bar without routing help.

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