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

Annotations already mark the tool as read-only and idempotent, and the description adds substantial behavioral detail beyond that: server-side restriction filtering by role, default exclusion of child moves, truncation with a descriptionTruncated flag, and GM-versus-player visibility. This gives an agent a realistic model of what the call will return and how permissions affect it.

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 front-loaded with the core purpose and then logically covers sorting, response shape, child moves, permissions, and membership. It is dense and occasionally restates schema details, but given the five parameters and nuanced behavior, the length is justified.

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 read-only listing tool with an output schema present, the description covers everything needed to call it correctly: default and alternate shapes, ordering, child-move handling, restriction filtering, and the membership prerequisite. No important behavioral gap remains.

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?

The input schema already provides 100% parameter coverage with detailed descriptions, defaults, and enums for order, detail, children, and limit. The tool description largely restates those defaults rather than adding new parameter-level meaning, so the high-coverage baseline 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?

States a specific action — listing play-by-email moves for a single campaign — and describes the result as 'the move feed', making the resource and scope unambiguous. This clearly separates it from sibling tools like play_get_move, which retrieves a single move, and play_list_session_moves, which is session-scoped.

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?

Provides strong contextual guidance: default feed shape, ordering behavior, full-detail option, child-move inclusion, and the campaign-membership requirement. It does not explicitly name alternative sibling tools or state when to prefer them, so it stops just short of fully explicit routing.

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