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

The description discloses side effects beyond annotations: the link is stored in the world's playCampaignIds[], house rules are shared both ways, characters are imported by default, and the tool returns 400 if the link already exists. It also specifies the required 'edit' access. This far exceeds the annotations' minimal hints and accurately describes the operation's behavior.

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 a single dense paragraph but front-loads the core purpose in the first sentence. Each subsequent sentence adds crucial operational detail (storage, house rules, permissions, error handling). It is not verbose or redundant, though it could be split into bullet points for easier parsing. Still, it is appropriately sized for the complexity.

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 tool's complexity—linking two entities, sharing house rules, importing characters, and requiring specific permissions—the description covers all key aspects: storage mechanism, side effects, default behavior, error cases, and access requirements. It also includes the output schema, so return values need not be explained. The description is fully sufficient for an agent to call this 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 description coverage is 100%, with each parameter already explained in detail (e.g., id and campaignId are Mongo _ids, importCharacters has a description of its effect and default). The tool description adds no new parameter-specific meaning beyond what the schema provides, so the baseline score of 3 applies.

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 the exact action 'Link a play campaign to a world' with clear verb and resource, and the detailed explanation of storage and effects distinguishes it from the sibling imagine_link_adventure_to_campaign. It 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 says when to call it ('call this only when you've confirmed the link isn't already present'), notes the required caller permissions (owner/gamemaster), and mentions the alternative of setting importCharacters to false to skip character import. It provides clear conditions for use and implies when not to use it.

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