set_item_length

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

No annotations are provided, so the description carries the full behavioral burden. It does not disclose whether this affects playback length by stretching or by trimming, whether the item's source is preserved, whether it requires the item to be selected, or whether the operation is reversible (undoable). For a mutation tool with zero annotation coverage this is a significant gap.

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?

Very short and front-loaded: the purpose sentence comes first, followed by one parameter note. No verbosity or repetition, though the docstring-style 'Args:' formatting is mildly noisy given only one parameter is described.

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 3-required-parameter mutation tool with no annotations and no output schema, the description leaves too much unspecified: two of three parameters are unexplained, the mutation semantics (trim vs stretch) are absent, and there is no guidance on when to use this over sibling item tools.

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 schema documents none of the three parameters. The description documents only 'length: New length in seconds' and says nothing about track_index or item_index, which the agent cannot infer are required track/item addressing identifiers. With 0% coverage it fails to compensate for the gap.

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: 'Set the length of a media item.' This distinguishes it from siblings like set_item_position, set_item_volume, set_item_fade_in/out. It does not explicitly differentiate from those siblings in the description, but the resource-plus-property naming makes the distinction reasonably clear.

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?

No when-to-use guidance and no exclusions. The description never says whether the item must be a take, whether the length is capped by source media, or which is preferable versus split_item or set_item_position when trimming. The agent gets no routing help among the many set_item_* siblings.

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