Update ad groups

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

Goes well beyond the annotations: it discloses that changes hit the live account, that current values are read first and old values preserved in the audit log, the confirmation gates that guard risky writes, and that targeting_spec is replaced wholesale rather than merged. These are exactly the behavioral facts an agent needs before issuing a mutation, and nothing contradicts the idempotentHint/destructiveHint declarations.

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-loads the operation and batch limit, then moves to parameter shape, then to guardrails — a sensible order with no filler. The telegraphic style ('Changes the live account.') is dense but every sentence carries distinct information.

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 batch mutation tool with an output schema already present, the description covers mutation scope, payload shape, unit conventions, audit behavior, and confirmation requirements. Only the ad_account_id parameter and any partial-failure behavior in a 500-item batch go unaddressed.

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 schema description coverage at 0% and an untyped free-form items array, the description carries the full burden and largely meets it: it defines the id-plus-changed-fields shape, gives two concrete examples, explains whole-spec replacement for targeting_spec, and decodes micro-currency for money fields. The remaining gap is ad_account_id, whose null default and selection semantics are never explained.

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 ('Update ad groups') plus a concrete batch ceiling ('up to 500 per call') and the fact that it mutates the live account. This separates it cleanly from the create_/archive_/list_ siblings without needing their schemas.

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 conditional guidance for the confirm parameter: 'APPLY' when bid/budget increases exceed PINTEREST_ADS_MAX_INCREASE_PCT or batches are large, 'ARCHIVE' when setting status ARCHIVED. It does not, however, route the agent between this tool and overlapping siblings like pinterest_ads_adjust_ad_group_bids, pinterest_ads_set_statuses, or pinterest_ads_archive_ad_groups.

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