append_to_timeline

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

With no annotations, the description carries the full burden. It discloses that append targets the current timeline and uses names, but does not explain failure modes, whether clips are inserted at the playhead or end, or what happens if names don't match. This is thin for a mutation tool.

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?

One sentence, no filler, directly states the operation and key qualifier. Perfectly concise and front-loaded.

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 1-param mutation tool with no annotations or output schema, the description is minimal. It omits prerequisites (current timeline existence), error handling, and behavior details like insertion position. This is insufficient for reliable 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?

The schema only defines clip_names as an array of strings with no description. The phrase 'by name' clarifies that the array elements are clip names used to identify clips, adding meaning beyond the schema. However, it doesn't specify the origin or validity requirements for these names.

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 ('Append') plus resource ('clips') and target ('current timeline'), with method ('by name'). It clearly distinguishes from related tools such as create_timeline or set_current_timeline, which serve different purposes.

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 implies usage: append to an existing current timeline, but does not explicitly state prerequisites such as having a current timeline set or alternatives like create_timeline_from_clips. There is no guidance on when not to use this tool, so the implied context is present but not elaborated.

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