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

The annotations already declare destructiveHint=true, so the mutating nature is known; the description goes further by disclosing that the undo is itself a change and therefore reversible ('undo the undo'), that repeated undos of the same change are refused, and one structural limit on what can be undone. These are non-obvious behavioral traits that no annotation or schema field carries.

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, front-loaded with the action and id source, then the reversibility rule, then the exception. Every clause carries information; only the parenthetical '(undo the undo to bring it back)' is mildly redundant with the preceding clause.

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 two-parameter mutation with an output schema available, the description covers the action, the id provenance, the reversibility model, and the failure/exception cases. There is nothing an agent needs to know to call this correctly that 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?

Schema coverage is 100%, so the baseline is 3, but the description adds provenance for change_id (originating from postkey_get_edit or postkey_edit_video) and clarifies that changes may belong to either the caller or another person, which the terse schema text ('The change id to undo, from the edit's changes') does not convey.

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 and resource ('Undoes one change to a video edit') with explicit scope ('one change', 'yours or the person's'), and distinguishes itself from postkey_edit_video by naming it as the restore alternative. An agent can tell this apart from postkey_edit_video or postkey_get_edit without opening a 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?

Gives the precondition for the change_id (from postkey_get_edit or postkey_edit_video), two explicit exclusion cases (already-undone changes are refused; the first auto-edit line cannot be undone as a whole), and routes the excluded case to a named alternative. When-not-to-use guidance is stated rather than implied.

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