get_directional_light_cascade_settings

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds value beyond them by disclosing the error behavior on wrong actor type and enumerating the returned fields, which is real behavioral context.

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-loads the verb and the set of settings, then gives the round-trip and error behavior. The Returns block is dense but justified given there is no output schema; no filler sentences.

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?

With no output schema, the description supplies the full return shape, plus error and round-trip behavior for a single-parameter read tool. Nothing an agent needs to invoke it correctly is missing.

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?

Only one parameter with 100% schema coverage; the schema already documents 'light_name'. The description's 'of a directional light' reinforces the type constraint but adds little syntax beyond what the schema provides, so baseline 3 applies.

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 (Read) and resource (the seven CSM settings of a directional light), enumerates exactly which settings, and names the sibling it round-trips (set_directional_light_cascade_settings). An agent can distinguish it from get_light_properties and configure_light_shadows 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?

Clearly frames this as the read counterpart of set_directional_light_cascade_settings and notes the actor-type constraint ('Errors honestly if the actor is not a directional light'). No explicit when-not-to-use or named alternative, but the context is clear enough to route correctly.

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