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

Beyond annotations (readOnlyHint=false, destructiveHint=true), the description adds that the campaign is created in PAUSED status and that 'No money will be spent until explicitly enabled', plus the confirm=true requirement. These are useful behavioral disclosures not captured in annotations, giving the agent a safety warning. It does not mention what happens when confirm=false (likely a dry-run), but the core safety and confirmation behavior is transparent.

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 description is two concise sentences plus a warning emoji. It front-loads the main action and the critical PAUSED status, then adds the confirmation requirement. Every sentence earns its place with no fluff.

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 7-parameter creation tool with no output schema, the description covers the core behavior (creation, PAUSED status, confirm requirement) but omits what the tool returns (e.g., campaign ID) and what occurs when confirm is false. Since output schema is absent, a note on return value would improve completeness, but the description is adequate for calling the tool with the required parameters.

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 86% with detailed descriptions for most parameters (confirm, language, dailyBudget, targetCountries, networkTargeting). The tool description only restates the confirm requirement already in the schema, and does not add meaning to the undocumented brandId parameter. With high schema coverage, the baseline of 3 is appropriate; the description adds negligible extra semantics.

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?

The description clearly states the verb 'Creates' and the resource 'search campaign in the user's Microsoft Advertising account', plus the PAUSED status. This distinguishes it from siblings like create_bing_adgroup (creates an ad group) and publish_campaign_to_microsoft_ads (publishes a draft). The title reinforces the search campaign scope.

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?

The description implies this is for creating a new campaign, but it does not explicitly contrast with alternatives such as create_campaign_draft or publish_campaign_to_microsoft_ads. It does mention the confirm=true requirement, which is a usage prerequisite, but lacks explicit 'when to use vs. not use' guidance. The purpose is clear enough that an agent would likely infer correct usage, but the guidance is not explicit.

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