set_light_paths

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

With no annotations, the description carries the full burden and mostly succeeds: per-parameter defaults, hard bounds (0 to 1024, 0.0 to 10.0), the noise/black-glass consequences of wrong values, and the patch-style merge behavior are all disclosed. It omits the precondition that Cycles must be the active engine and whether settings persist to the saved file.

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 summary sentence plus compact Args block where every line earns its place. The trailing 'Returns: Dict with the light path settings' is redundant given that an output schema already exists, a small waste.

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 mutation tool with no annotations and a null-default optional schema, the description is nearly complete: semantics, defaults, limits, merge behavior, and effects are covered, and the return value need not be explained because an output schema exists. The missing engine precondition keeps it below 5.

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 coverage is 0% (property titles only), so the description must do all the work, and it documents all nine parameters with meaning, defaults, and ranges, including the easily confused glossy vs diffuse vs transmission distinction and filter_glossy's 0.0-10.0 float range. Nothing in the schema is left 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?

States a specific verb and resource ('Set Cycles light bounce limits and caustics') and ties the scope to the Cycles engine, which implicitly separates it from the sibling set_eevee_light_path. An agent can identify the target of the operation without opening the schema.

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?

Gives real operational context: fewer bounces render faster, glass/liquid needs enough transmission bounces or turns black, and 'Leave anything unset to keep it' makes the partial-update contract explicit. It never names an alternative tool or an engine-switch precondition, so 5 is not warranted.

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