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 and world-scope profile is covered. The description adds the 'by keyword' search model, but does not disclose pagination behavior (though end_cursor exists) or result characteristics. With annotations doing the safety lifting, a 3 is appropriate.

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 efficient sentence that front-loads the core action and resource, then lists optional filters. No filler or 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 explained in the description. With annotations covering safety, schema covering parameters, and a clear core purpose, the definition is nearly complete. The only mild gap is lack of sibling-differentiation guidance, which would help in this large tool family, preventing a full 5.

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%, so every parameter including query, fields, end_cursor, most_recent, and videos_live is documented in the schema. The description only echoes the filter concept; no additional format, syntax, or constraint details are provided beyond the schema. Baseline 3 per the 100%-coverage rule.

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 (Search) and resource (Facebook videos) plus scope qualifiers (by keyword, with recency and live filters). The 'search' verb makes it clearly distinct from sibling get_* tools that retrieve known resources (e.g., facebook_get_group_videos, facebook_get_page_videos).

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?

Usage is implied: use this when you have a keyword and want to discover videos. However, there is no explicit guidance on when to prefer this over content-specific siblings like facebook_get_group_videos or facebook_get_page_videos, nor exclusions for the filters.

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