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

Annotations already declare destructiveHint=true and readOnlyHint=false, but the description adds real value beyond them: pre-send verification of operation kind, approval integrity and state drift, plus the 'reconciled without replay' constraint. It doesn't describe return format or failure modes in detail, but the added behavioral guardrails are 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?

Three tight sentences, front-loaded with the destructive action and followed by the prerequisite and reconciliation constraints. Every sentence carries information; nothing is padded.

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 destructive confirm-step mutation with no output schema, the description covers the action, the prerequisite, the internal verification, and post-failure handling. It is nearly complete, with only the opaque connection_context parameter 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 coverage is only 33% (customer_id documented, draft_id and connection_context undocumented). The description gives draft_id useful semantics (must be a matching draft from the prepare call), but connection_context and the draft_id format remain unexplained, so it only partially compensates for the coverage gap.

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 ('remove an existing Performance Max retail listing tree and replace it with the approved tree'), which is far more than a restatement of the name. It also implicitly distinguishes itself from its prepare sibling by requiring a prior draft.

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 gates usage on 'explicit approval' and 'a matching draft from google_ads_retail_tree_replace_prepare', clearly naming the prerequisite tool. It also implies a when-not (drafts that don't match are rejected) and points to reconciliation for uncertain outcomes, though it doesn't name the reconcile tool directly.

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