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

Annotations already cover the safe-read profile (readOnly/idempotent/non-destructive), and the description goes well beyond them: the 'view' access requirement, the 403 exception for members of linked play campaigns and the exact minimal recaps-only shape returned, and the substituted `hasLinkedCampaigns` boolean for non-owner viewers. This is unusually rich disclosure of authorization and response variance.

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?

Purpose and the campaign-link caveat are front-loaded, and every sentence carries substantive information rather than filler. It is long, and spelling out exact response shapes overlaps with the existing output schema, but nothing is wasted.

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 single-id read tool this covers permissions, the alternate response shapes, the informational nature of campaign links, and pointers to the follow-up tools. With an output schema present, it need not describe return values further, so the description is complete.

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% for the single `id` parameter, which the schema already documents as the Mongo `_id`. The description's 'by id' adds no syntax or format detail beyond that, so the baseline 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?

Opens with a specific verb and resource ('Fetch one adventure by id') and enumerates the payload contents (settings, ruleset, recommended level, linked play campaigns). This distinguishes it from siblings like imagine_list_my_adventures and imagine_get_adventure_page without needing to open either schema.

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?

Gives clear conditions: caller needs at least 'view' access, and it routes to imagine_list_adventure_parts for sibling parts and imagine_get_adventure_recaps for the recaps-only shape. It also warns the campaign link is informational and not auto-synced. It stops short of an explicit 'prefer X over Y' rule against adjacent getters, so it is strong but not exhaustive.

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