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

Annotations already indicate a mutation (readOnlyHint=false) with idempotent and non-destructive behavior. The description adds valuable behavioral context beyond annotations: 'All players will see the new scene' and 'Only one scene can be active at a time,' which implies deactivating the previously active scene. This is meaningful side-effect disclosure.

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?

Three sentences, each earning its place: the action, the player-visible side effect, and the ID lookup instruction. The most important information is front-loaded, with no redundant or filler content.

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 simple one-parameter activation tool with supportive annotations, the description covers the core action, the side effect, the lookup prerequisite, and the exclusivity constraint. It does not mention return values or error cases, but those are not essential for correct invocation given the tool's simplicity and the absence of an 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?

The input schema has 100% description coverage, with sceneId described as 'Scene ID to activate (use scene-list to find)'. The tool description repeats the same guidance ('Use scene-list to find available scenes and their IDs') without adding new parameter-level semantics. Baseline 3 is appropriate since the schema already fully documents the parameter.

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: 'Switch the active scene in Foundry VTT.' It also clarifies the exclusive nature ('Only one scene can be active at a time') and the player-visible effect, clearly distinguishing it from sibling tools like scene-list, scene-get, and scene-set-door-state.

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 provides explicit guidance to use scene-list to find available scenes and their IDs, which is the key prerequisite for calling this tool. It implies the correct workflow (list first, then activate) but does not explicitly mention when not to use this tool or name alternative tools other than scene-list.

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