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

The description adds substantial behavior beyond annotations: it explains the two-way call flow, that the controller writes to playCampaignIds[], that characters are imported by default, that duplicates cause a 400, and that edit access on the world is required. This is exactly the kind of side-effect and error-context information an agent needs.

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?

Every sentence in the description earns its place: the core action, the two-way mechanism, the default import behavior, the duplicate-error condition, and the access requirement. It is dense but well structured and front-loaded with the primary purpose.

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 what the tool does, how it behaves, when to call it, what could go wrong, and the required permission. The output schema is available, so not describing the success return is acceptable. The combination of annotations, schema, and description is complete for invoking this 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 schema already documents all parameters. The description adds extra value by clarifying that importCharacters defaults to true and controls character ref import, and by tying campaignId to a play campaign. This meaningfully goes beyond the raw schema descriptions.

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 uses a specific verb and resource, 'Link a play campaign to a world', and adds meaningful detail about the two-way sync and character import behavior. It is clearly distinguished from sibling tools like imagine_unlink_world_from_campaign and imagine_link_adventure_to_campaign by naming the exact objects involved.

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 explicit call conditions: only call after confirming the link doesn't already exist, or be prepared to handle a 400. It also explains when to set importCharacters to false. It does not explicitly compare against the sibling link tool for adventures, but the guidance is otherwise clear and actionable.

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