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

Adds substantial behavior beyond the annotations: exact quota semantics (total_alerts includes paused/expired, max_total_alerts is a hard cap, remaining=0 makes create_alert fail and pausing does not free a slot), the exclusion of route legs, and the fact that no tool can change a plan. These are precisely the facts an agent needs to avoid mis-summarising or suggesting impossible remedies.

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?

Front-loads purpose and return contents, then uses labeled sections for the disambiguation blocks, so it is easy to skim. The PLAN NAMING and PLAN CHANGES material sits somewhat tangentially on a simple list tool, but each block guards against a plausible agent error and no sentence is purely 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?

An output schema exists, yet the description still supplies the interpretive context the schema cannot (French 'essai' = permanent free tier, tier_label is the display name, quota counters overlap paused/expired alerts). Nothing needed to call or correctly report on this tool is missing.

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?

Only one optional boolean (active_only) and schema coverage is 100%, so the schema already carries the meaning. The description references active status in its field list but adds no filter syntax or default behavior, matching the baseline for fully documented params.

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+scope: the signed-in user's cancellation alerts, ordered newest first, and enumerates the fields each carries (park, date window, nights, active status). It explicitly distinguishes itself from list_my_itineraries and list_routes, which an agent could otherwise confuse it with.

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 concrete routing guidance: 'Check it before summarising what they watch or suggesting something be deleted,' and points to list_my_itineraries for route alerts and quota.route_alerts for counts. Lacks explicit when-not-to-use framing against siblings like get_alert, but the context is clear.

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