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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context beyond that: the campaign link is informational only and not auto-synced, and the caller must have view access. These details help the agent understand the tool's side effects and authorization requirements, which annotations do not provide.

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 three sentences with no waste. The first sentence states the primary purpose and return content, the second clarifies a critical caveat, and the third states a permission prerequisite. It is front-loaded and every sentence earns its place.

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 has an output schema (indicated) and only one parameter, the description is complete for correct invocation. It covers what the tool returns, the caveat about campaign links, and the required access level. No essential behavioral or usage information 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% for the single parameter 'id', which is described as 'Mongo _id of the world'. The description does not add additional semantics beyond restating that it fetches by id; it does not provide format examples or extra constraints. Since the schema fully documents the parameter, a baseline score of 3 is appropriate.

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 clearly states the verb 'Fetch', the resource 'world', the identifier 'by id', and enumerates the specific data returned (settings, membership, user-linked play campaigns). It differentiates from sibling tools like imagine_get_world_page or imagine_list_my_worlds by specifying the exact scope and fields, so an agent can distinguish it without opening other schemas.

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 a clear context: it is for fetching a single world by id with specific details, and it explicitly states the permission requirement ('Caller must have at least view access'). However, it does not explicitly mention when not to use it or name alternatives (e.g., imagine_list_my_worlds for listing), so it lacks explicit exclusions but still gives clear usage context.

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