Set the Gamemaster's targets

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

Beyond the annotations, the description discloses key behavioral traits: replace semantics, clearing behavior on empty lists, player-visible side effects, roll integration, and operational prerequisites. It aligns with the annotations (write operation, idempotent setting, non-destructive in the resource-deletion sense) and adds meaningful context about consequences.

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 carry all essential information, with the primary action front-loaded and supporting details (effects, prerequisites) following logically. No filler or redundant restatement of the title or schema.

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 two-parameter tool with full schema descriptions and annotations, the description covers prerequisites, side effects, clearing behavior, and downstream use in rolls. There is no output schema, but nothing critical for invoking the tool 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 adds value by clarifying that tokenIds accept both ids and namescars, which the schema's 'Tokens to target' string description does not explicitly convey. The sceneIdentifier semantics are already well covered by the schema's optional-check explanation.

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 opens with a specific verb and resource ('Replace the Gamemaster's targeted tokens on the viewed scene'), clearly distinguishing it from sibling token tools like move-token, update-token, or toggle-token-condition. It also specifies the mechanism (ids or names) and the empty-list clearing behavior, leaving no ambiguity about what the tool does.

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 clear context: this is for replacing the GM's targets on the current scene, and it explains why it matters ('Players see the target marks, and later rolls use them'). It also states prerequisites ('Allow Write Operations' and the drawn canvas), though it does not explicitly name alternatives or when-not-to-use scenarios.

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