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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds the locale defaulting behavior and field list but little beyond the defaults and return shape, which the schema and output schema largely cover. Adequate but not rich added context.

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, zero waste, front-loaded with purpose then parameters then alternative routing. Each sentence 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?

An output schema exists, so return values need not be explained in depth. All parameters are covered, and alternative engines are named. Only minor gaps in when-not-to-use guidance remain.

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 the schema already documents all six parameters, making 3 the baseline. The description reinforces count/page and locale defaults but adds no syntax or format detail beyond what the schema provides.

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 states a specific verb and resource ("Search Google's public video results page") and details the returned fields (title, platform, link, duration, age). It also names the sibling alternatives (bing_videos, brave_videos), so an agent can distinguish it from other engine tools without opening schemas.

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?

It explicitly routes the agent to alternatives: "Use bing_videos or brave_videos to search another engine." That is clear conditional guidance, though it doesn't state tool-level exclusions beyond engine preference (e.g. when a dedicated video site tool would be preferable).

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