append_media

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

No annotations are provided, so the description carries the behavioral burden. It discloses the core mutation and that omitting track_index/record_frame appends at the end of the timeline. However, it does not mention side effects like automatic track creation or what occurs if both paths and media_ids are omitted.

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 tight: two sentences with zero filler. The main purpose is front-loaded, followed by an actionable usage tip and a clear pointer to the relevant alternative.

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?

The description covers the primary use case and the key deviation from add_image, but it is not fully complete for a no-annotation tool with 5 parameters. Missing context around create_track and source-required semantics leaves an agent guessing on edge-case invocations.

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 0%, so the description must compensate. It does clarify that track_index and record_frame can be omitted to append at the end and that sources can be paths or media_ids. Yet it leaves create_track's meaning unexplained and does not state whether at least one source is required.

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 names a specific verb ('append'), a clear resource ('timeline'), and the accepted source types ('media pool ids or absolute file paths'). It also distinguishes itself from 'add_image' by explicitly reserving stills for that sibling tool. This makes the tool's purpose immediately distinguishable.

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 explicitly says to use 'add_image' instead for still images, and explains when track_index and record_frame should be omitted. It does not, however, explain when to choose this over import_media or whether media already needs to be in the media pool.

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