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

Annotations only indicate the tool is non-read-only and non-idempotent. The description adds useful behavioral detail about pixel coordinates being relative to the top-left corner of the grid cell and provides the coordinate conversion formula. It does not disclose side effects beyond placement, but no annotation contradiction exists.

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 purposeful sentences with no filler. The core action appears first, followed by coordinate semantics and prerequisite lookup instructions. Information density is high and all content helps the agent call the tool correctly.

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?

Given the 8-parameter schema is fully described and there is no output schema, the description covers the non-obvious relationships: coordinate conversion and ID lookup. The optional sceneId default is already documented in the schema. It is sufficiently complete for an agent to invoke the tool correctly.

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. The description adds meaning beyond the schema by explaining the grid-to-pixel calculation and by explicitly connecting actorId to actor-list/actor-filter and gridSize to scene-get. This extra relational context improves parameter understanding.

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: 'Place a token on the scene for an actor.' This clearly identifies a creation action and distinguishes it from sibling tools like token-move, token-update, and token-delete. The actor/scene framing also separates it from actor-create.

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 gives concrete prerequisite guidance: use scene-get to find gridSize and actor-list or actor-filter to find actorId. It also explains how to convert grid coordinates to pixels. It does not explicitly name alternatives like token-move or token-update for when-not-to-use, but the creation context is clear enough.

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