Search YouTube

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations by disclosing the high API quota cost: 100 of 10,000 units per call, compared to about 1 for other tools. This is valuable for an agent deciding whether to use search liberally. It doesn't mention pagination or response shape, but the annotation coverage lowers the bar.

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, no wasted words. The core purpose and filters are front-loaded in the first sentence, and the quota warning is placed second as a relevant operational note. Every clause 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 search tool with 7 parameters, no output schema, and moderate complexity, the description covers the purpose, scope, filter dimensions, and an important quota caveat. It does not describe the result format or pagination, which an agent might need, but the annotations cover safety/idempotence and the schema covers parameter constraints. The description is mostly complete for correct invocation.

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 only 29%, so the description must compensate. It does: 'date' maps to published_after, 'region' maps to region_code, 'channel' maps to channel_id, and 'sort order' maps to order. It also treats 'query' as the keyword and 'videos, channels or playlists' maps to the type enum. max_results is not semantically explained in the description, but the schema's minimum/maximum/default provide enough operational detail.

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 clearly identifies the verb 'search', the resource 'YouTube', and the exact scope: videos, channels, or playlists by keyword. It also lists the filter dimensions (date, region, channel, sort order), which distinguishes it from sibling tools like get_videos or trending that suggest direct retrieval rather than keyword search.

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 description implies the primary use case clearly: keyword-based discovery across YouTube content types. It does not explicitly name when to prefer search over siblings such as get_videos or trending, nor does it state exclusions, so it falls short of explicit when/when-not guidance. However, the keyword framing provides enough context for an agent to select this tool over direct retrieve-by-ID siblings.

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