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

With no annotations, the description carries the full burden and does well: it discloses that data is live and uncached, what categories of information are included (parent statuses, review feedback, issues, delivery summary), and that feedback is conditional on disapproval. It doesn't cover auth or error behavior, but for a read-only status check this is solid.

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, each earning its place: the first states the core purpose, the second details return content and freshness, the third gives the use case. The description is front-loaded and free of filler.

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?

Given no output schema, the description explains the return value at a useful level: parent ad set and campaign statuses, review feedback, active issues, and a human-readable summary. It could be more precise about exact result fields or error cases, but for a simple two-parameter read tool it is largely complete.

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 only 50%: ad_account_id is documented but ad_id is not. The description doesn't explain how to obtain or format ad_id, nor does it add meaning beyond the parameter name. The phrase 'single Meta ad' names the resource but provides no additional parameter guidance.

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 specific verb ('Check'), resource ('a single Meta ad'), and the exact dimensions of status covered (delivery, review, effective). It clearly separates this from sibling tools like get_ad_review_status by emphasizing the broader status scope plus parent statuses and issues.

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?

Explicitly states when to use the tool: 'monitor ads after creation or diagnose delivery problems.' It does not name alternatives or exclusions, but the use context is clear enough for an agent to select it over most siblings.

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