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

Adds behavior beyond the annotations: the operation produces a new booking with a new UID (returned here) and notifies attendees. This is meaningful for a destructiveHint=true tool, since it tells the agent the identity of the record changes. It still never states what happens to the original booking (cancelled? soft-deleted?), which is the most consequential unknown for a destructive call.

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 short sentences, front-loaded with the action, then the side effects, then the routing hint. Every sentence carries distinct information and nothing is padded.

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 covers the return value (new UID) and attendee notification, and the schema covers parameters. The one gap is the disposition of the original booking, which matters given destructiveHint=true; otherwise this is complete for a 4-parameter mutation.

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 all four parameters are already documented, including the ISO 8601 format and confirmation behavior of rescheduledBy. The description adds no parameter detail and even introduces a near-miss name ('bookingUidToReschedule') that belongs to find_available_slots, not this tool. Baseline 3.

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 ('Move a booking to a new start time') and immediately distinguishes itself from create_booking by disclosing that Caly creates a NEW booking with a new UID rather than editing in place. An agent can differentiate it from siblings like create_booking, cancel_booking, and get_booking without opening a 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?

Explicitly routes the agent through the prerequisite workflow: 'Find a free time with find_available_slots, passing bookingUidToReschedule.' That is real when-to-use guidance. It stops short of stating when NOT to use it (e.g. use cancel_booking + create_booking for a different event type), so it lands at 4 rather than 5.

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