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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the description adds little beyond them. It does not disclose side effects, failure conditions (e.g., what happens if the campaign ID is invalid), reversibility, or permission requirements. For a mutating operation, the description carries a burden to explain behavioral traits, which it fails to do.

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 a single, front-loaded sentence with no redundant words. It efficiently conveys the core action and key parameter without waste. Structure is clean and scannable.

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 tool with 6 parameters, no output schema, and no additional context, the description is too brief. It omits important details like the meaning of brandId, the effects of optional parameters (biddingStrategy, networkTargeting) and their defaults, and any potential errors or side effects. The description does not provide enough information for an agent to use the tool confidently.

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 50%, with only name, targetCpc, and campaignId having schema descriptions. The description mentions 'target CPC bid' but does not clarify the other parameters (brandId, biddingStrategy, networkTargeting) or their relationships. It fails to compensate for the low coverage, leaving half the parameters unexplained.

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 states a specific verb ('Creates'), a resource ('ad group'), and the context ('under an existing Microsoft Advertising campaign with target CPC bid'). This clearly differentiates it from sibling tools like create_bing_campaign (campaign creation) and add_bing_keywords (keyword addition). No ambiguity.

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 phrase 'under an existing Microsoft Advertising campaign' implies a prerequisite (campaign must exist) but does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions or conditions like 'do not use if campaign does not exist'. It gives context but lacks explicit guidance.

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