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

Annotations already cover the safe-read profile (readOnlyHint, destructiveHint=false), yet the description adds genuinely new behavioral context: rows are immutable, the log survives deletion of the booking itself, and an actor of `system` means an automated expiry rather than a person. That last point is the kind of interpretation detail an agent cannot derive from structured fields.

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 sentences, zero filler, and the core scoping/ordering facts are front-loaded before the interpretive guidance. Nothing is repeated from the schema or annotations.

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 must carry return-shape information; it supplies event types, ordering, and the actor column, but does not describe the remaining per-row fields. Still, for a two-param read tool this covers nearly everything an agent needs.

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% and both parameters carry their own descriptions (including the default of 100 and the product-scoping behavior). The description echoes ordering ("newest first") and column scope but adds no syntax or format detail beyond the schema, so the 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+resource: the immutable event trail for bookings (held, confirmed, cancelled, expired), newest first, with the actor. This is unmistakably distinct from siblings like hub_get_booking_rules or hub_get_booking_availability, which are configuration/availability rather than history.

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?

Gives an explicit when-to-use trigger: "Use it to answer 'what happened to this booking'," and further clarifies actor semantics for interpreting `system`. It does not name a sibling alternative or state when NOT to use it, so it falls short of a 5.

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