item_get_start_end

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

The readOnlyHint annotation already signals this is a safe read operation; the description adds the specific return values (start frame, end frame, duration), which is useful context. But it does not disclose behavior for invalid/missing item names, track types, or index boundaries, and it doesn't explain the frame origin (0-based vs 1-based). No contradiction with annotations.

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 a single, compact sentence that immediately states the tool's purpose and returned data. Every word earns its place, with no filler or redundancy.

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 simple getter with an output schema and full parameter documentation, the description is sufficiently complete. The tool has low complexity, and the combination of description, schema (100% coverage), and readOnlyHint leaves no major gaps in understanding what the tool does and how to call it.

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 description coverage is 100%, and the schema already explains item_name, track_type, and track_index. The description adds no additional parameter detail beyond the schema, such as how item_name relates to timeline context or how track_type/track_index affect lookup. It does not compensate for or expand on the schema's meaning.

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 ('Return') and resource ('timeline item') and clearly states the exact data returned: start frame, end frame, and duration. This distinguishes it from sibling tools like item_get_duration, which only returns duration, and item_get_properties, which returns a broader set of properties.

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: any time you need start, end, or duration of a timeline item. However, it does not explicitly state when to prefer this over item_get_duration or item_get_properties, nor does it mention any exclusions or alternative tools. No explicit 'when' or 'when-not' guidance is given.

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