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

Annotations cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=true), and the description usefully adds that changes are dry-run against Google and that the live account is untouched. It does not describe failure behavior or what the stored proposal looks like, but the added behavioral context is substantive.

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-loaded with the core behavior (dry-run, nothing changed) before the supported-types list, and every sentence carries operational weight. The trailing type list is partly redundant with the schema but is a reasonable quick reference.

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 2-parameter but structurally complex tool, the description covers the approval workflow and the no-op guarantee well. However, the 'Supported' list omits remove_negative_keywords, which the schema accepts, risking an agent believing that operation is unsupported, and there is no output schema or mention of validation-failure outcomes.

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 nested change union and required fields are already fully documented; the description's only added value is enumerating change types. That enumeration is also incomplete — it lists six types but the schema supports seven (remove_negative_keywords is omitted), so it slightly under-informs rather than compensating.

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 specific verbs and resources: it validates changes against the live account, dry-runs them with Google, stores them as a proposal, and returns a summary. This is clearly separable from siblings like apply_changes, discard_proposal, and undo_changes without opening any 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 explicit workflow guidance: show the summary to the user and apply only after approval, which implies the handoff to apply_changes. It does not name apply_changes or discard_proposal directly or state what to do on validation failure, so it stops short of full when/when-not routing.

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