ass_add_line

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

With no annotations, the description carries the full behavioral burden and does so well: it discloses accepted time formats, clamping into the document timebase, the `end < start` error condition, that lines append at the end, that the index is 0-based, and that the operation is snapshot-backed and undoable.

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?

Front-loads the core action, then layers time semantics, error conditions, undo behavior, and return shape in tight, non-redundant sentences. Every sentence 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?

An output schema exists, so return values need not be re-explained, yet the description usefully summarizes the payload. Error and undo semantics are covered; the main gap is the undocumented non-timing parameters for what is a 12-param tool.

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 coverage is 0% across 12 parameters, so the description must compensate. It thoroughly explains the two timing params (accepted formats, clamping, ordering error) but leaves ten parameters (text, layer, style, effect, comment, margins, doc_id, actor) undefined in both schema and description.

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+resource: 'Append a new line.' Clear and unambiguous. However, it does not differentiate from the sibling ass_add_lines (bulk add), leaving the agent to infer which to pick when adding one vs many.

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 explicit when-to-use guidance, no prerequisites, and no routing to the closely-named sibling ass_add_lines for multi-line insertion. The only contextual hint is that ass_undo reverts the call.

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