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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions 'Browser-based tool', which provides a minimal hint about how the tool operates, but it does not disclose whether the tool is client-side, read-only, or what happens to the input data. This is a significant gap for a tool with no annotations.

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 a single, efficient sentence that front-loads the core action and output format. Every word earns its place, with no wasted content.

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's simplicity (no parameters, no output schema), the description is largely sufficient. The 'Browser-based tool' qualifier is useful context for invoking it. However, it could have mentioned the expected input format (e.g., timestamps or duration markers) to fully eliminate ambiguity for an agent.

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?

There are zero parameters in the schema, so the baseline is 4. The description adds semantic value by explaining the tool's input (video segment boundaries) and output (YouTube chapter format), which gives an agent a clear conceptual model of the tool's functionality even though no formal parameters exist.

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 states the tool's function with a specific verb and resource: it takes video segment boundaries as input and outputs them in YouTube chapter format. This distinguishes it from siblings like timestamp-generator, which serve a related but different purpose.

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 gives no explicit guidance on when to use this tool versus alternatives such as timestamp-generator or youtube-description-generator. The only hint is 'Browser-based tool', which indicates it is UI-driven but does not help an agent choose among YouTube-related tools.

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