set_lumen_gi_quality

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

Annotations already carry the safety profile (readOnly=false, idempotent=true, destructive=true), so the bar is lower, and the description adds genuine context by showing the cvar/value mapping and stating that the value is 'read back' after setting, indicating post-write verification. It stops short of explaining persistence, editor-session scope, or why the operation is flagged destructive.

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?

The description is front-loaded with the action and mode requirements, then the per-mode mappings, then the return shape. It is dense but each block earns its place; the inline arrow formatting is slightly raw 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 2-parameter tool with 100% schema coverage and full annotations, the description is complete: it names the operation, the exclusive modes, the cvar/value mapping, and even the return shape in the absence of an output schema. Nothing essential to invoking 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?

Schema coverage is 100%, so the baseline is 3, but the description goes beyond the schema by mapping each enum value to its underlying cvar and numeric value (e.g., quality -> scalability group 0..4; method None/Lumen/ScreenSpace -> 0/1/2), which is real added meaning. The mutual-exclusivity note duplicates the schema, capping it below 5.

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: 'Applies Lumen / global-illumination scene tuning via console variables,' naming the exact cvars (sg.GlobalIlluminationQuality, r.DynamicGlobalIlluminationMethod) it targets. It is functionally precise, but it does not distinguish itself from adjacent tools like set_cvar, set_scalability_quality, or set_post_process_setting that an agent might reasonably confuse it with.

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 description supplies a usage constraint ('Provide exactly one of') and the two mutually exclusive modes, which implies how to call it, but never states when this tool is preferable to alternatives such as set_cvar or set_scalability_quality. Usage is implied rather than routed, matching a 3.

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