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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: confirm=false previews (a dry-run mode) and that hours are interpreted in the account's time zone. It does not state whether the call replaces an existing schedule or errors if one exists.

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?

The purpose and rationale are front-loaded, then parameters are documented compactly with no filler. Every sentence adds information an agent needs.

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?

With an output schema present, return values need not be described. For a mutation tool with a 7-parameter schema and annotations covering safety, the description supplies the missing parameter syntax, semantics, dry-run behavior, and motivation — nothing critical is absent.

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 description coverage is 0%, so the description carries the full burden and largely meets it: it defines days syntax including the 'weekdays'/'weekend'/'all' shorthands, from_hour/to_hour range and time-zone basis, and the bid_adjustment percentage convention with an example. account_id and campaign_id are left undocumented but are self-evident identifiers.

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 ('Sets WHEN a Microsoft (Bing) campaign is allowed to serve') and scopes it to Microsoft, which implicitly separates it from the sibling set_ad_schedule (Google) and get_ad_schedule (read). An agent can identify the operation immediately.

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?

Explains the operational context clearly ('Without an ad schedule the campaign runs 24/7 and burns budget at night'), which tells the agent when this is warranted. It stops short of explicitly naming the alternative tools or prerequisites, so it is clear context without full routing guidance.

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