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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds the Meta Ad Library as the source, but says nothing about pagination via end_cursor, result limits, or rate behavior, so it stays at the annotated baseline.

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?

A single front-loaded sentence with no filler; the scope and primary filters are stated immediately with zero redundancy.

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?

An output schema exists, so return values need not be described, and the schema fully documents all 8 optional parameters. The only gaps are the absence of guidance on pagination looping and on choosing between query and ad_page_id when both are optional.

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% for all 8 parameters, so the schema does the documentation work. The description restates keyword, page ID, country, status, and date but omits sort_data and end_cursor, adding no syntax or default information beyond the 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?

Names a specific verb (Search), resource (ads), and the data source (Meta Ad Library), plus the two alternative lookup keys. It does not differentiate itself from nearby siblings such as facebook_ads_keywords or facebook_ads_archive_details, but an agent can still tell what this tool returns.

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?

There is no when-to-use or when-not-to-use guidance and no mention of alternatives, even though facebook_ads_keywords and facebook_ads_archive_details sit right next to it. Usage is only implied by the listed filter fields.

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