reels_render

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

The caching disclosure (identical content/settings reuse a cached export) is genuinely useful behavioral context beyond the annotations, and the async nature is stated. However, for a non-read-only tool with no output schema, it omits the key operational detail: what handle or job identifier is returned to poll with reels_render_status, and whether re-queuing a changed revision supersedes an in-flight render.

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?

Three short sentences, front-loaded with the action and immediately followed by the two facts that change agent behavior (caching, non-blocking return). Nothing is padded or restated from the title.

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?

This is an async mutation with no output schema and undocumented parameters, so the description must cover the return handle, revision precondition, and resolution options. It covers only the caching and non-blocking aspects, leaving the agent unable to complete the queue-then-poll workflow from the description alone.

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% across two parameters, so the description carries the full burden and does not meet it. It never mentions projectId or that width is restricted to 270/540/1080 with a default of 1080, leaving the agent to discover the export resolution constraint only from the raw 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?

"Queue an MP4 export of the current revision" gives a specific verb (queue an export) and resource (MP4 of the current revision), which is distinct from read-only siblings like reels_preview or reels_get_asset. It stops short of naming reels_render_status as the polling counterpart, so the boundary with siblings is only implied.

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?

"Returns immediately" implies this is asynchronous and that a status check is needed, but the description never says when to call it versus reels_preview or reels_render_status, nor does it state the prerequisite that the revision must already be committed. Usage is inferable but not explicit.

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