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

Beyond the annotations (which only say it is a non-read-only, non-destructive, closed-world write), the description discloses the duplicate-name refusal, that out-of-scope screenIds are skipped silently, that groups carry no permissions, and the required `screen.edit` permission.

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 definition of the resource before mechanics and routing. Dense but each clause (uniqueness, permission, cross-location semantics) carries distinct information; only slightly long for a single-create tool.

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?

An output schema exists so return values need no explanation. The description covers authorization, failure mode, member-add semantics, and sibling routing, leaving no obvious gap for an agent to call this correctly.

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%, so name, screenIds and description are already fully documented. The description only restates that members are optional via screenIds; it adds no format, limit or interaction 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 and resource ('Create a named screen group') and immediately defines what the resource is ('a saved set of screens you handle together'). The clarification that a group is a flat label that grants no permissions distinguishes it from location-tree or permission constructs.

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?

Explicitly routes the agent: add members later with add_screens_to_group, and use assign_screen_to_node to change where a screen lives. It also states the precondition that creation is refused on a duplicate name, so the agent knows when this call will fail.

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