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

Annotations already cover the safety profile (readOnly/idempotent/non-destructive), and the description adds substantial extra context: per-caller visibility rules (public + own private vs admin-sees-all), omission of campaigns with no tagged sessions, and the exact empty-result shape ({ campaigns: [] }). This is behavior beyond what structured fields 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?

Front-loads the core action and grouping semantics, then layers permission and edge-case detail. Dense but every sentence carries information; the permission enumeration is somewhat long but not padded.

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?

Output schema exists so return values needn't be spelled out, yet the description still gives the grouping shape and empty case. Permission model, visibility scoping, and omission behavior are all covered — nothing an agent needs to call this correctly 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% and the single `id` param is fully documented there as the Mongo `_id` of the adventure, so baseline 3 applies. The description clarifies the entity relationship (sessions tagged via imagineAdventureId) that determines the result set but adds no format or syntax detail about the parameter itself.

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?

States a specific verb+resource ('Fetch the play-session recaps ... grouped by linked play campaign') and explicitly distinguishes itself from the manual alternative (play_list_campaign_sessions + play_list_pages). An agent can tell what this returns and how it differs from the sibling list tools without opening the 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?

Names the read-through-to-play condition (caller must be a member of a linked campaign or an admin with Admin Mode on), notes the recaps-only path for PRIVATE adventures, and states it replaces the two-step manual walk of the sibling tools. When-to-use and the alternative are both explicit.

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