Query video search performance

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds a scope/attribution rule (where video impressions are counted), which is useful, but says nothing about data latency or result-size behavior beyond what the annotations and schema already convey.

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?

Two sentences, both earning their place: the first front-loads what the tool returns and by which dimensions, the second front-loads the scope boundary. No filler, no restatement of the title.

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, and the schema covers parameter semantics and enum constraints. The description supplies the one thing structured fields cannot – the reporting-scope boundary – leaving only minor gaps around data freshness, which data_state already handles.

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 (site_url resolution rules, date defaults, data_state, aggregation_type, row paging) is already documented in the schema. The description adds no parameter-level detail beyond that, which is the baseline 3 case when the schema does the heavy lifting.

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 resource (Videos tab performance in Google Search) with the exact metrics returned (clicks, impressions, CTR, average position) and the breakable dimensions. The closing sentence distinguishes it from web-search reporting, so an agent can tell it apart from query_search_analytics without opening either schema.

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 negative scope statement ('Video results shown on the main web results are counted under web search, not here') tells the agent when this tool is the wrong choice, which is real routing value. It stops short of naming the alternative tool explicitly, so it is clear context rather than full when/when-not/alternatives guidance.

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