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

Annotations already cover readOnly/idempotent/non-destructive. The description adds genuinely useful behavior: restricted moves return 404 for non-listed players, while the GM and Admin Mode admins bypass restrictions, and it discloses that children scenes are filtered the same way. That is real value beyond the annotations.

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-loaded with the core action and return shape, and every sentence carries information. The last two sentences overlap somewhat in restating access rules, which keeps it just short of a 5.

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?

With an output schema present, return values needn't be explained, and the description still covers the important edge case (404 for restricted moves) and the full permission model. Nothing essential for a correct call 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 there is a single parameter whose schema already documents it as the Mongo `_id`. The description only echoes 'by id', adding no syntax or format detail beyond the schema, 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?

States a specific verb (Fetch) and resource (one move by id) and further specifies the return shape (full markdown body plus a children array of split-party child scenes). This clearly separates it from list-type siblings like play_list_campaign_moves and play_list_session_moves.

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?

It gives clear context for use ('by id', filtered children) and extensive access conditions, but never explicitly routes the agent away from alternatives such as play_get_page or play_list_campaign_moves. Clear context, no explicit when-not, so a 4.

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