search_ad_library

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is fully covered. The description adds behavior the annotations cannot: a hard cap of 25 results per request with an instruction to paginate, plus a summary of what the response contains (preview URLs, advertiser details, targeting info, impression stats). It does not mention auth requirements or rate limits, but the cap-and-paginate note is genuinely useful.

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?

Purpose is front-loaded in the first sentence and the practical constraint (25-result cap) is stated plainly. The second sentence ('Find and analyze real ads from any advertiser...') largely restates the first with marketing flavor, and the return-value inventory is a touch listy, but nothing is confusing or bloated.

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 14-parameter, zero-required, open-world search with no output schema, the description does solid work: it compensates for the missing output schema by naming the returned fields and warns about the pagination limit. It stops short of explaining default behaviors (e.g., the implicit recent date window) or how multiple filters combine, which would fully close the gap.

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 100% across 14 parameters, so the schema already documents syntax, formats, and defaults in detail. The description only enumerates filter categories (keyword, advertiser, country, date range, targeting facets, impression range), which maps to the schema but adds no meaning beyond it. Baseline 3 applies.

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 ('Searches the LinkedIn Ad Library for ads matching criteria') and immediately scopes it to 'real ads from any advertiser across different countries and time periods'. This is unmistakably distinct from every sibling, all of which operate on the caller's own accounts, campaigns, or creatives.

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 conveys the research context (analyze any advertiser's ads across countries/time periods), which implies when it is useful, but it never states an explicit when-to-use condition or names an alternative among the siblings. No exclusions or prerequisites are given, so the agent must infer the intended use case.

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