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

Annotations declare this is a non-read-only mutation, and the description adds context beyond them: an authorization requirement (owners only, sign-in needed), a financial side effect (a no_show waives the Latchbell fee), and a visibility side effect (done counts toward what customers see). It does not say whether the transition is reversible or what notifications fire, which keeps it from a 5.

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?

Short and front-loaded, with the auth constraint placed before state semantics where an agent needs it. The phrasing is telegraphic and the second clause lacks a verb, which costs a little readability without adding waste.

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 two-parameter mutation with no output schema, the description covers the authorization gate and the consequences of two states, which is the most valuable content. It leaves open what marking does operationally — whether it can move a booking backwards, whether it is idempotent, and how booking_id is obtained — so it is adequate but not 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 0%, so this description carries the full burden. It does explain the semantics of three of the four enum values (arrived/started as progression, no_show's fee waiver, done's customer-visible effect) but says nothing about booking_id — its format, where to get it, or whether it accepts partial IDs.

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?

The description gives the resource (a booking) and enumerates the states (arrived, started, done, no_show), so an agent can infer this sets a booking's progress state. But it never states the action verb directly — 'How far a booking has got' is a noun phrase, not 'set the booking status to...' — and it does not distinguish itself from siblings like booking_status, check_in, or cancel_booking.

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 states a real prerequisite ('Owners only, needs sign-in'), which genuinely gates usage. It offers no when-to-use vs when-not guidance and never mentions alternatives such as booking_status (read) or cancel_booking, leaving the agent to infer the boundary from sibling names.

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