render_start

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

With no annotations, the description itself must disclose behavior. It does provide meaningful behavior: the render is asynchronous, local, based on a durable JSON snapshot, and restarts from the beginning if interrupted. This goes beyond a generic tool description, though it omits details like return values, cancellation behavior, and whether an existing render is replaced.

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 compact and front-loaded, with the main action stated first. Every sentence adds information: 'asynchronous local render' sets the core behavior, and the durable snapshot/restart note is valuable context. There is no redundancy or filler.

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 tool that starts an asynchronous process, the description does not state what the call returns or how an agent should later retrieve the render result (e.g., via render_status or render_get_output). It covers the start semantics and interruption behavior, but lacks the return-value and follow-up context needed to use the tool end-to-end.

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 input schema has one required parameter, comp_id (a UUID), but the description provides no additional meaning for it. With schema description coverage at 0%, the description should compensate by clarifying that comp_id identifies the composition to render, but it does not. The parameter name is somewhat self-explanatory, but the description adds no semantic value.

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 and resource: 'Start an asynchronous local render.' It clearly states the action and object, and the 'async' qualifier helps set expectations. However, it does not explicitly distinguish itself from related sibling tools like render_status or render_cancel, so the differentiation is only implicit.

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 when to use this tool: when you want to begin a render. It also implies that the render is asynchronous, which suggests pairing with status-checking tools. However, it does not explicitly name alternatives or state when not to use it, leaving the usage decision mostly to inference.

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