Gemini Youtube Summary Tool

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

Annotations already declare readOnlyHint=true, so safety is covered. But the description adds nothing else: it doesn't mention that the URL must be a YouTube link, any rate limits, output format, or how the model/style parameters affect behavior. With annotations covering the safety profile, the description should still provide more behavioral context but fails to do so.

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?

The description is extremely concise (one sentence) and front-loaded with the core action. It could be slightly more informative without losing conciseness, but it's efficient.

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 tool has an output schema and annotations, the description doesn't need to explain return values. However, it lacks any context about limitations or usage relative to the many sibling tools, and doesn't mention that only YouTube URLs are supported. For a tool in a crowded namespace, this is incomplete.

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 parameters (url, model, style) are already documented in the schema. The description adds no additional meaning beyond what the schema provides, which is acceptable given full coverage, but it still scores a baseline 3.

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 (summarize) and resource (YouTube video), which is clear. However, it doesn't differentiate itself from the sibling gemini_youtube_tool or gemini_summarize_tool, leaving ambiguity about which tool to pick for YouTube summarization versus general summarization.

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?

No guidance is given about when to use this tool versus the numerous sibling tools. The description doesn't state prerequisites, limitations, or alternatives, leaving the agent to guess based on name alone.

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