set_item_position

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

With no annotations provided, the description carries the full burden. It explains the accepted item ID types and the measure:beat,fraction syntax, which is helpful. However, it does not disclose behavior when both position_time and position_measure are provided, what happens on invalid inputs, or any side effects. This is partial behavioral transparency.

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 structured with a one-line summary, an 'Item Identification' section, and an 'Args' section. It is reasonably concise, but there is redundancy: the item identification section repeats the info in the item_id parameter explanation. Minor confusion with track_pos_idx as a non-parameter name, but overall it earns its place.

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 all four parameters and their optionality, which is good given the tool has moderate complexity. It does not clarify precedence when both position_time and position_measure are supplied, and it omits error behavior. Since an output schema exists, the description doesn't need to cover return values. Overall, it is fairly complete but with some edge-case gaps.

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 fully. It does: track_index is defined as 'Index of the track', item_id as 'EITHER integer track_pos_idx OR string direct_item_id', position_time as 'New position in seconds', and position_measure with an explicit format and example. This adds significant meaning beyond the plain schema.

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 opens with a clear, specific statement: 'Set the position of a media item.' It specifies the resource (media item) and the action (set position), distinguishing it from sibling tools like set_item_length. Additional details about item identification methods further clarify the scope.

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 provides clear context on how to use the tool, including two item identification methods and two position formats, but it never mentions when to prefer this tool over alternatives or when not to use it. For example, it doesn't compare with get_item_properties or set_item_length. Usage context is implied but no explicit exclusions or alternatives are given.

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