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

The readOnlyHint annotation already establishes this is a safe read. The description adds useful behavior beyond that by noting recurring patterns are included when they fall in the window and that the default range is now-to-two-weeks. It stops short of describing pagination, result limits, or ordering, so it is a modest addition over the annotation.

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?

Three tight sentences, each earning its place: what the resource is, the default scope, and the backing endpoint. The scope semantics are front-loaded before any implementation detail.

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 no output schema, the description correctly carries the burden of explaining what comes back (availability events including recurring patterns), and it discloses the default window so an agent can invoke it with zero arguments. It omits return shape detail and pagination, which keeps it just short of complete.

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 every parameter is already documented in the schema (including the managers-only constraint on include_all and the default caller for user_id). The description only restates the default window, adding essentially no semantics beyond the schema. 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 ('List availability events') and then defines what an availability event actually is — when people said they can or cannot work, including recurring patterns in the window. That framing cleanly separates it from siblings like list_shifts or list_time_off_requests without needing 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?

It conveys the default scope ('defaults to the caller, from now to two weeks out'), which implicitly tells the agent the tool works out-of-the-box with no arguments. However, it gives no explicit when-to-use versus alternatives such as list_eligible_users_for_shift, and no guidance on when to widen the window or use include_all.

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