create_chapter_markers

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

With no annotations, the description carries the full burden and does so well. It explicitly discloses that originals are removed, that resulting markers have duration 0, and that the returned activeSequence identifies the actual sequence used. These are exactly the side effects and output traits an agent needs to know before invoking.

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 compact and front-loaded with the core action, then gives the use case, destructive side effect, and output detail. No sentence is wasted; the activeSequence explanation is useful and 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 one-optional-parameter tool with no output schema, the description is complete. It explains the input prefix, the transformation, the destructive behavior, and the important return value field, plus why that field matters. Nothing essential is missing 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 coverage is 100%, so the schema already documents the single optional prefix parameter and its default. The description re-states the default but adds no meaningful semantics beyond what the input schema provides, matching the baseline for full schema coverage.

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?

States a specific verb and resource: converting duration markers into POINT markers of type MARKER_TYPE_CHAPTER. The phrase 'Originals are removed after the chapter markers are created' further distinguishes this from generic marker add/remove siblings, so an agent can select it correctly without opening other tools.

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?

Provides a clear use case: turning 'Scout/Key:' moments into YouTube/podcast chapter markers. It does not explicitly name alternatives or exclusion conditions, but the intended context is concrete and readily actionable.

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