post_reel

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

Despite no annotations, the description discloses several critical behaviors: it blocks while Instagram processes the video, processing usually takes 30 seconds to 2 minutes, progress is reported, and local files are uploaded directly to Meta's servers. This is substantial behavioral context beyond the schema.

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 three concise sentences with no filler. It front-loads the primary action, then covers the key parameter constraint, and finally the blocking/progress behavior. 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?

For a tool with four optional parameters and no output schema, the description gives enough to call it correctly: the video source constraint, the blocking behavior, and progress reporting. The remaining parameter meanings are covered by the schema.

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 description adds critical meaning beyond the schema by requiring exactly one of video_url or video_path and explaining the difference: video_url must be publicly reachable, while video_path is a local file requiring no hosting. This compensates well for the 50% schema coverage, though caption semantics are left largely to the 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?

The description opens with the specific verb 'Publish' and resource 'a Reel,' making the tool's purpose immediately clear. It also differentiates from siblings by emphasizing immediate publishing and blocking behavior, distinguishing it from schedule_reel and post_story.

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 clearly conveys when to use this tool: to publish a Reel now, not schedule it. It does not explicitly mention alternatives like schedule_reel or post_story, but the context and blocking behavior make the intended usage unambiguous.

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