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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value by disclosing the data shape (status, review status, serving holds, metrics), which is genuinely useful beyond the annotations. It says nothing about pagination, row caps, or how the summary/full detail mode changes output volume, which the schema covers only partially.

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?

One dense sentence with the resource front-loaded and results listed in a compact parenthetical, followed by a short filter clause. No filler sentences. The nested parentheses ('Ads (creatives) ... performance (spend, results, ...)') are slightly harder to parse but still efficient.

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 nine optional parameters, no output schema, and read-only annotations, this definition is adequate but thin. The description does the important work of naming the returned fields, which compensates for the missing output schema. It leaves out anything about result volume, ordering, or how the 'detail' mode affects the response, which matters for a list tool with a summary/full switch.

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 89%, so the schema already carries the parameter documentation burden. The description adds only marginal meaning, reinforcing that 'campaign' is the primary filter and identifying which metrics appear in results. That is consistent with the baseline 3 for a high-coverage 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?

The description names a concrete resource (LinkedIn ads/creatives) and enumerates the exact fields returned: status, review status, serving holds, and performance metrics (spend, results, leads, CTR, CPC). It also states the supported filter ('Filter by campaign'). It does not explicitly contrast itself with close siblings like linkedin_campaigns or linkedin_performance, so an agent must infer that this is the ad-level, not campaign-level, retrieval tool.

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?

'Filter by campaign' implies the intended narrow use, and the mention of period performance implies a reporting context. However, the definition never says when to prefer this over linkedin_performance, linkedin_breakdown, or linkedin_campaigns, and gives no exclusions. Usage is inferable but not stated.

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