ass_new_document

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

With no annotations, the description carries the full burden and does reasonably well: it discloses that the document is registered, that a doc_id is auto-generated when omitted, and enumerates the exact return payload (with line indices 0-based). It stops short of stating whether the new document becomes the active/selected document or whether anything is written to disk before a save.

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 opening line is front-loaded and efficient, but the trailing enumeration of ~15 return fields largely duplicates the existing output schema and consumes space without adding selectable information. Structure is docstring-style rather than tuned for tool selection.

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 zero-required-parameter creation tool with an output schema, the description supplies the parameter meanings and mutation/registration semantics. The main omission is the relationship to sibling lifecycle tools (open, select, close), which would help an agent sequence calls correctly.

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, and it covers all four parameters: play_res_x/play_res_y as the new script's resolution, doc_id as an optional registry id that is generated when omitted, and script_type with its two concrete values and default (v4.00+ ASS vs v4.00 SSA).

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 first line states a specific verb and resource ('Create ... an empty ASS document') and adds the registration effect, which clearly separates it from file-opening siblings like ass_open. It does not name any sibling explicitly, but the 'empty/new' scope is unambiguous.

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?

There is no when-to-use guidance, no prerequisites, and no routing to alternatives such as ass_open for existing files or ass_duplicate_lines. Usage must be inferred from the verb alone.

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