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

No annotations are provided, so the description carries the full burden and does so: 503 failure mode within ~40s, no charge on failure, 6h caching, third-party seller, and 0.02 USD per call via x402. These are exactly the operational traits an agent needs before invoking a paid, flaky endpoint.

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?

Front-loads the action and scope in the first sentence, then layers operability facts in subsequent clauses. Dense and largely waste-free, though the middle sentence is a long run-on that packs several distinct facts together.

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 paid third-party scraping tool with 8 optional params and no output schema, the description covers pricing, caching, failure behavior, return volume, and a fallback source — nothing an agent needs to decide or call correctly is missing.

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 100%, so baseline is 3; the description earns extra by explaining the cost profile of includeDetails (slower, more failure-prone, keep maxItems small) and the 20-ads-per-call cap. It doesn't elaborate on keyword/advertiser interaction beyond what the schema states, so not a 5.

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 ('Search the LinkedIn Ad Library... by advertiser name or keyword') and enumerates the returned fields. It also names the alternative ad source '/v1/ads/meta' relative to the meta_ads sibling, so an agent can route correctly.

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 frames when this is the right choice (advertiser/keyword search with optional country and date filters), when it is risky ('LinkedIn sometimes blocks automated access'), and which tool to prefer for reliability ('/v1/ads/meta is the more reliable ad source'). The includeDetails caveat tells the agent to keep maxItems small.

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