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

Annotations already flag a non-read-only, open-world, non-idempotent operation; the description adds the concrete side effect (Cal.com sends the calendar invitation, Meet link created) and the 30-minute duration and host. It stops short of saying what happens on a duplicate or conflicting slot, which matters given idempotentHint=false.

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?

Two sentences, zero filler, with the core action and its external channel front-loaded and the safety precondition placed last as the gating rule. Every clause carries independent information.

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?

For a 6-parameter mutation tool with no output schema, it covers the actors, the external side effect, and the confirmation gate. The remaining gap is return/error behavior (e.g. what identifier comes back, how a taken slot fails), which the description leaves unaddressed.

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 coverage is 100%, so every parameter including start, name, email, notes, language and timeZone is already documented in the schema. The description only reiterates that start comes from get_availability and that name/email identify the attendee, adding little beyond structured fields, so 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 (books a 30-minute intro video call), names the host and channel (Google Meet / Huntay AzerTürk), and anchors the slot to get_availability. An agent can distinguish this from read-only siblings like get_availability or list_services immediately.

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 ties invocation to a precondition: the slot must come from get_availability and the user must have confirmed both slot and details. That sequencing plus the 'call only after' exclusion is exactly the when/when-not guidance an agent needs before a side-effecting booking.

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