set_cycles_sampling

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

With no annotations, the description carries the full burden and does well: it discloses partial-update semantics, numeric ranges and defaults for every setting, the speed/noise tradeoff of noise_threshold and the clamp values, and a real constraint ('path_guiding: ... CPU only'). It does not say whether the scene must already be using Cycles or what happens if it isn't, which is the main remaining behavioral gap.

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?

Front-loaded one-line purpose, then a compact per-argument list where every line carries operational value. The trailing 'Returns: Dict with the sampling settings after the change' is largely redundant with the output schema, a small amount of waste in an otherwise tight definition.

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 nine-parameter, zero-required partial-update tool with no annotations, the description supplies ranges, defaults, tradeoffs, one environment constraint, and update semantics — everything an agent needs to call it correctly. Return values are covered by the output schema.

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 compensate entirely, and it does — all nine parameters get meaning, valid range, default, and effect (e.g. clamp_indirect: '10 is Blender's default; lower removes fireflies', time_limit: '0 to 86400. 0 means no limit'). This is exactly the information the bare schema lacks.

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?

States a specific verb and resource — 'Tune how Cycles spends samples' — and immediately distinguishes itself from the closest sibling by delegating sample count to set_render_samples. An agent can tell this is the adaptive-sampling/quality tuning tool, not the resolution tool.

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?

Explicitly routes the agent to set_render_samples for the raw sample count and states the partial-update rule ('Leave anything unset to keep it'), which is the key invocation pattern. It stops short of naming alternatives for noise cleanup at the render setting level (e.g. set_denoising) or stating prerequisites like the Cycles engine being active.

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