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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so 'Changes nothing' is reinforcement rather than new information. The description does add real behavioral context beyond the annotations: the required access scope and the underlying POST endpoint, plus the shape of the violation payload.

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 purpose, then the return content, then the side-effect guarantee, permission requirement, and endpoint in three compact fragments. Nothing is padded and no sentence is redundant with the tool name.

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?

There is no output schema, and the description compensates by describing the returned violation kinds and the isBypassable flag. Combined with permission scope and the no-side-effects guarantee, an agent has everything needed to call it 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% and there is a single required array parameter, so the schema already carries the semantics. The description's 'for each driver id' confirms batch semantics but adds no format, bound, or ordering detail beyond what maxItems/minItems already state.

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?

Names a specific verb ('Check whether drivers are available to be planned') and resource (drivers), and states concretely what comes back (vehicle violations, HR violations, isBypassable). It does not differentiate itself from the very similarly named sibling cxt_validate_driver_for_orders, which is the only thing keeping it from a 5.

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?

The phrase 'available to be planned' implies the pre-planning context, and the required ITINERARY_PLANNING_ACCESS scope is stated, but there is no explicit when-to-use/when-not guidance and no mention of when to prefer the singleton cxt_validate_driver_for_orders or how this relates to cxt_plan_orders.

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