Channel and video analytics

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavior beyond that: a ~2-day data lag and the 28-day default window. It does not describe pagination or result shape, so it is solid but not rich.

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-loaded with purpose, then a compact enumeration of reports, then defaults and lag. Dense but every clause carries information; the long report list is slightly list-heavy but earns its place.

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 10-parameter, no-output-schema analytics tool, the description covers report selection, defaults, and the key conditional dependency (retention→video_id). Minor gaps remain around sort and max_results behavior, but an agent has enough to call it correctly.

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 70%, and the description meaningfully compensates: it explains what each report value returns, that retention needs video_id, and that metrics/dimensions/filters apply only to custom. It leaves sort and max_results unexplained, which keeps it below 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 ('YouTube Analytics for the channel or one video') and enumerates the exact report types it can produce, which lets an agent distinguish it from get_video or get_channel at a glance.

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?

Gives concrete usage context: defaults to the last 28 days, retention requires video_id, and custom requires your own metrics/dimensions. It does not explicitly say when to prefer this over sibling tools like get_video, so it stops short of full alternative routing.

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