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

Annotations already declare destructiveHint=true and openWorldHint=true, but the description adds real value by disclosing the exact confirmation gates for each mutation path (restrict vs widen/replace vs empty-list removal) and by stating the overwrite semantics of "Replace." It does not say whether the prior schedule can be recovered or whether a dry run is the safe preview path.

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, no filler, with the core replace semantics front-loaded before the confirmation conditions and the empty-list edge case. Every clause carries operational meaning.

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, open-world mutation with no output schema, the definition covers the risky decision points (confirmation thresholds, removal semantics, time-zone scoping). Minor gaps remain around return values and error behavior, but nothing essential to invoking it correctly 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?

With schema coverage at 60%, the description compensates by explaining that hours are evaluated in the account time zone, that bid adjustments are optional and per-entry, and — most importantly — that an empty schedule list means removal back to 24/7. It says nothing about campaign_id or account resolution, leaving those to the schema.

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?

Specific verb ("Replace") plus resource ("a campaign's ad schedule") plus scope (days and hours, account time zone, optional bid adjustments). The word "Replace" distinguishes it from partial-update siblings like google_ads_update_campaign and from the bid-only tools such as google_ads_set_device_bids.

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 routing: restricting a 24/7 campaign runs directly, while widening or replacing an existing schedule requires confirmation, and an empty list removes the schedule (also requiring confirmation). It does not name alternative sibling tools (e.g., update_campaign) for agents weighing which tool to call, so it stops short of full when/when-not guidance.

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