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

The description adds a useful behavioral detail beyond the annotations: the effect lands on the segment's scene immediately and does not require build_scenes. However, it does not disclose whether calling it again replaces an existing SFX or stacks another one, which matters for a mutating tool with idempotentHint=false.

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 tight sentences with no filler. The main action is front-loaded, the parameter lookup hint is embedded compactly, and the important immediate-effect behavior is stated last.

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 three-required-parameter tool with no output schema, the description gives the agent enough to select and invoke the tool correctly: what it does, where to get the track ID, and what happens after the call. The main omission is behavior around repeated calls or replacement semantics.

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 fully documents project_id, segment_number, and library_track_id. The description adds little beyond what the schema says, except reinforcing that the track ID comes from browse_audio_library with category='sfx'.

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 uses a specific verb ('Attach'), a specific resource ('a sound effect from the audio library to a segment'), and names the source library lookup path. This clearly distinguishes it from siblings like add_music_track or update_segment_content.

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 tells the agent how to obtain the required track ID via browse_audio_library(category='sfx') and that no build_scenes step is needed afterward. It does not explicitly name an alternative like add_music_track for music, so it falls just short of full when-to-use coverage.

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