add_fade_track_to_sequence

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

Annotations cover the safety profile (non-destructive, not read-only, not idempotent), so the bar is lower, and the description still adds real value: it discloses the get-or-create behavior for the track and that the operation persists via the 'saved'/'save_error' return fields. It does not explain why a repeated call would be non-idempotent (e.g. whether a duplicate section is appended), which is the one behavior an agent most needs here.

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?

Two sentences, purpose first, return shape second, with zero filler. Because there is no output schema, the inline 'Returns:' block is doing necessary work rather than padding.

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-parameter mutation with no output schema, the description covers what it creates, the get-or-create nuance, and the full return shape including the save_error path. The remaining gap is operational context: when this tool should be preferred over manually adding a section, and whether repeated calls accumulate sections.

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 is a single parameter with 100% schema description coverage ('Name of the target Level Sequence'), so the schema already carries the meaning. The description adds no format, resolution, or lookup semantics for sequence_name beyond what the schema states.

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 ('Adds ... root fade track with a fade section spanning the playback range'), which is enough to separate it from siblings like add_visibility_track or add_weighted_value_track. It does not explicitly name those siblings, so the differentiation is implicit rather than stated.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternative track-adding tools. The only implicit hint is the get-or-create phrasing 'Adds (or returns the existing)', which tells the agent it can call it without checking first, but that is inference, not guidance.

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