event_undo_revision

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

Annotations already declare destructiveHint=true and readOnlyHint=false, and the description adds substantial context beyond that: events and words are never removed, the REVISION_NOT_REVERSIBLE failure mode including the concurrent-writer case, and the fact that the call itself records a revision.reverted Revision. This is unusually rich behavioral disclosure.

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?

Dense single paragraph, but front-loaded with the action and every clause carries information (scope, exclusions, error, side effect, iteration). Slightly overpacked for a quick read, hence not 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?

No output schema exists, yet the description explains the return (the recorded revision.reverted Revision), the preconditions, the failure code, and the retry/walk-back pattern. Nothing essential for correct invocation is left implicit.

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% and the actor field carries a detailed description in the schema, so the baseline is 3. The description only loosely ties revisionId to the change being undone and adds no format or sourcing detail beyond what the schema already states ('from event_get_revisions').

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 precise verb+resource (undo the latest change of an Event) and immediately narrows scope to the reversible revision kinds (field.changed, parent.added, parent.removed), which distinguishes it from siblings like event_get_revisions and event_add_parent. An agent can tell exactly what this does without opening the 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?

Explicitly says when it applies (latest not-yet-undone reversible change), when it does not (event.created, account.added, an undo, or anything else), and what to do on failure (read the Event again and reconsider). It also explains how to walk further back by calling again on the next change.

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