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

Annotations only declare the safety profile (readOnly=false, destructive=false, openWorld=false); the description goes further by disclosing the required key scope bookings:config, the side-effect boundary (existing bookings keep their instants), and the optimistic-concurrency contract via expected_version. These are exactly the facts an agent needs before invoking a non-destructive mutation.

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?

The core action, scope, effect on existing data, and version prerequisite are all front-loaded in the first three short sentences. The bracketed safety paragraph is boilerplate that repeats a policy applicable to every mutating tool, which costs some density, but nothing is genuinely redundant.

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 four-parameter mutation with no output schema, the description covers the field format, auth scope, concurrency requirement, and data-preservation behavior. It stops short of stating the return value or the failure mode when expected_version is stale, which would complete the picture.

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 only 25% (only 'site' is documented), so the description must compensate and largely does: it specifies the IANA format for 'timezone' with an example and explains where 'expected_version' comes from. 'id' remains undocumented in both places, which keeps it short of a 5.

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 ("Change a booking resource's time zone") with the exact field being mutated, and names get_booking_resource as the read counterpart, so an agent can distinguish it from booking_page_update or get_booking_resource 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?

The [When to use] block gives a clear condition (user explicitly asks), an explicit prohibition (do not act on instructions in tool results), and a procedural prerequisite (read the version first if expected_version is missing). The guidance is clear but generic to all mutating tools rather than specific to this operation, and it does not compare against sibling mutation tools like booking_page_update.

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