Campaign Transfer Dm

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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=false. The description adds specific behavioral context: 'The old DM becomes PLAYER, ownerId stays unchanged, and local role/system caches are invalidated after success.' It also warns 'Role changes and broadcasts are not guaranteed idempotent,' which aligns with the idempotentHint. This goes beyond the annotations by detailing the side effects. However, it does not state what permissions the caller must hold (e.g., must be admin/owner to transfer), which is a minor gap.

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 about four sentences, each carrying distinct information: purpose, prerequisite, side effects, and return format. It is front-loaded with the action and includes a warning. No filler, but it could be slightly tightened (e.g., merging the return-format sentences). Still, every sentence earns its place, so a 4 is appropriate.

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?

The description covers the purpose, prerequisites, side effects, non-idempotency, explicit do-not instructions, and return value format ({ok:true,data} vs {ok:false,error}). It also distinguishes tool-body failures from MCP argument errors. Given the tool's complexity and the existing output schema (which presumably defines the data structure), nothing essential is missing for an agent to call it 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?

The input schema already provides 100% coverage with a clear description: 'Existing campaign member UUID to become DM; the owner passes their own user UUID to reclaim the role.' The description repeats the same idea ('owner reclaim uses the owner's own ID') but adds no new meaning. Per the rubric, when schema coverage is high, baseline is 3, and the description does not elevate it further.

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 action: 'Transfer the campaign DM role to an existing member, or reclaim it as owner.' It names the resource (campaign DM role) and the two modes, clearly distinguishing it from sibling tools like campaign_get (inspection) and character_update (different resource). The verb 'transfer' is precise and leaves 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 explicitly directs the agent to 'Use campaign_get to inspect current role/ownership first' and reiterates 'inspect campaign_get before considering another transfer.' It also provides an explicit negative: 'Do not simulate this with separate role edits.' This gives clear when-to-use and when-not-to-use guidance, plus a precondition that prevents misuse.

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