Search YouTube

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-network profile is covered. The description adds only that video metadata (title, link, channel, views, etc.) comes back, which is largely redundant with the output schema; it discloses nothing about quotas, rate limits, or result quality.

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 front-loaded sentence with no filler, and the verb+resource leads. The trailing field enumeration is partly wasteful given an output schema exists, keeping it just short of a 5.

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?

With an output schema and annotations carrying the return shape and safety profile, the description only needs to establish purpose, which it does. The gap is the absence of any usage guidance for a tool with no alternatives, which is a minor omission.

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% and every parameter (query, country, language, max_results) is documented in the schema with defaults and bounds. The description adds no parameter-level detail, so the baseline 3 applies.

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 names a specific verb (Search) and resource (YouTube videos) and even enumerates the return fields, so the agent knows exactly what the tool produces. There are no sibling tools to differentiate from, so nothing further is required on that front.

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 only implied: the agent can infer it should call this to find videos on YouTube, but the description gives no when-to-use framing, no exclusions, and no indication of what to do when the query is too broad or returns nothing.

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