search_videos

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

No annotations are provided, so the description carries the full burden. It goes beyond the basic read-only implication by disclosing the concrete quota cost, the sign-in/API-key requirement, and the surprising auto-routing behavior. These are exactly the kind of behavioral traits an agent needs to compare with alternatives before calling.

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?

Three sentences with no filler: purpose, cost-plus-alternative, auth, and routing. Each sentence earns its place and the most important differentiator (cost/alternative) comes first.

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?

Given the lack of annotations and output schema, the description covers the crucial facts: what it does, when not to use it, auth, cost, and a non-obvious parameter interaction. It doesn't spell out the exact return format, but the primary invocation requirements are fully addressed.

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?

With 80% schema description coverage, the baseline is 3. The description adds valuable inter-parameter behavior — query is optional when channel_id is present, and channel_id without query routes to the cheap uploads path. This goes beyond the schema's individual parameter descriptions and explains how parameters interact.

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?

The description says 'Full-text search across YouTube' — a specific verb and resource. It distinguishes the tool from list_channel_uploads by drawing a sharp contrast: use that when you only want recent channel uploads. An agent can identify the tool's role without opening the 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?

Explicitly instructs when to avoid this tool and use list_channel_uploads instead, states the auth requirements up front, and explains the automatic routing when channel_id is given without query. Nothing is left for the agent to infer.

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