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

The parenthetical that screens pick up new artwork at their next daily check-in is a genuinely valuable behavioral disclosure: it tells the agent the change is eventually consistent and not immediately visible. Annotations already cover the safety profile (non-destructive, idempotent), so the description is not obligated to restate it. It still omits what happens when both optional fields are supplied or neither.

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?

A single sentence, front-loaded with the primary action and with every clause earning its place; the propagation detail is worth its parenthetical. It is slightly under-specified for a tool with two optional mutation paths, which prevents a 5.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. The remaining gap is invocation correctness: with only booking_id required, an agent is not told what happens if both creative_id and campaign_name are given, or if none is.

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 100%, so the schema already documents all three parameters, setting the baseline at 3. The description adds the meaningful nuance that the two optional fields are alternatives ('or') and that creative_id is 'another creative', but the exclusivity is only hinted at rather than specified, so it does not rise above the baseline.

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 names two concrete operations on a specific resource: swapping a booking's artwork and changing its campaign name. That is far more informative than the title alone and cleanly distinguishes it from bookings.create, cancel, or pay. It does not explicitly contrast itself with siblings, which keeps it 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?

Usage is implied by the two stated capabilities, and the schema points at bookings.upload_artwork as the source of a creative_id, giving an implicit prerequisite. However there is no explicit when-to-use/when-not guidance, no mention of which sibling to pick for other booking mutations, and no statement about calling this versus re-creating a booking.

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