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

The description supplies useful behavioral context (auth requirements, that acknowledgement preserves evidence and does not retract a sent notice). However, it explicitly states "Repetition is idempotent," which directly contradicts the annotation idempotentHint=false, making the safety/behavior profile self-inconsistent.

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 consecutive sentences ("Preserve the event and its evidence. Preserve the event and observation.") are near-duplicative and waste space, and the idempotency sentence conflicts with annotations. The auth preamble is front-loaded well, but overall the text is redundant and muddled rather than tight.

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 mutation tool with no output schema, the description does cover auth prerequisites and some post-conditions, which is more than the annotations alone provide. Still missing are clear consequences of acknowledgement, return behavior, and any resolution of the idempotency contradiction it introduces.

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?

With 100% schema description coverage, the schema already documents both parameters (id sourced from list_tabs, positive history event number). The description adds nothing about parameter meaning, so the baseline of 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?

The description states a specific verb and resource ("Acknowledge an expected event") and clarifies semantics like suppression of the notice. It does not, however, name or differentiate itself from nearby siblings such as domain_history or apply_domain_alerts, so the agent must infer the boundary.

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?

There is implied usage context ("expected event", "suppress its notice only if sending has not started") that hints at when acknowledgement is appropriate. But no alternative tool or explicit when-not guidance is offered, so routing between this and related history/alert tools is left to inference.

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