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

Annotations already declare the idempotent, non-destructive write profile, and the description adds real context beyond them: the occupancy value must remain within the existing quote, and the call is only valid pre-completion. It doesn't say what happens to fields that are omitted (partial vs. full replacement).

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 short sentences, the write nature front-loaded and the precondition trailing. Nothing repeats the annotations verbatim or wastes tokens.

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?

The lifecycle guard is covered, but with a nested booker object at 0% schema coverage, no output schema, and no statement about partial-update semantics or the quote constraint's error behavior, an agent still has to guess at invocation details.

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%, and the description only glosses two of the four parameters ('occupancy' and 'booker'). It never mentions session_id, the required booker sub-fields (first/last name, email), or that children may be set independently of adults.

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 specific mutable fields (occupancy, booker) on the booking session and leads with 'WRITE', so the agent can distinguish it from complete_booking_session or cancel_booking_session. The resource is never named explicitly, which keeps it just short of a 5.

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?

'before completing' and 'Not allowed after completion' give a clear lifecycle window plus an explicit exclusion. The alternative tool (complete_booking_session) is implied rather than named, so it misses the top band.

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