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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without the prose. The only added behavioral detail is the scoping word "caller's", implying it returns only the authenticated user's schedules rather than others' – useful but thin.

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?

A single colon-led sentence that leads with the action and resource, then lists the returned fields. Every clause carries information and there is no filler.

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 usefully enumerates the return shape (working hours per weekday, date overrides, time zone, default flag), which is exactly the compensation needed. It stops short of saying whether multiple schedules can be returned or how they are ordered, but coverage is strong for a zero-arg read.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline for a 0-param schema. The description instead spends its words on payload contents, which is a reasonable use of the space.

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?

Specific verb ("List") plus a precise resource ("the caller's availability schedules") and even enumerates what a schedule contains. The resource is clearly disjoint from siblings like list_event_types, list_bookings, and find_available_slots, so an agent can pick it without opening any 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?

The description states what is returned but never says when to call it instead of a neighbor such as find_available_slots or list_event_types. There is no exclusion, prerequisite, or alternative-selection rule, leaving the agent to infer usage entirely.

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