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

Annotations flag destructiveHint and non-idempotency, but the description adds the critical operational facts: REMOVED deletes the campaign, cannot be re-enabled, kills name changes, reporting history is retained, only passed fields change, and confirm=false is a dry-run. This is rich disclosure well beyond the structured hints.

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 action, then details in a logical order (rename, status, destructive semantics, partial-update behavior, dry-run). Dense but nearly every sentence carries required guidance; slightly long but not 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?

Output schema exists so return values need not be described. For a destructive mutation tool, the description covers irreversibility, partial updates, dry-run, and field interactions, leaving nothing essential missing for correct invocation.

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 0%, so the description carries the burden, and it explains name (new value, must be unique in account), the status enum values, confirm as dry-run, and the REMOVED-ignores-name interaction. It leaves customer_id and campaign_id unstated, a minor gap for two identifier parameters.

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 ('RENAMES a Google Ads CAMPAIGN and/or changes its status') and explicitly positions itself against siblings, calling out update_ad_group and update_campaign_status. The agent can distinguish it from update_campaign_status without opening either 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 what update_campaign_status cannot do ('renaming'), gives the motivating scenario (merging campaigns, changing naming conventions), and advises 'pause first if you are unsure' before an irreversible REMOVED. When-to-use and when-to-be-cautious are both covered.

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