Publish Facebook Page Reel

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

Annotations already indicate this is a mutating operation (readOnlyHint=false). The description adds valuable behavioral context: 'Video must be hosted on a publicly accessible server' and 'FB Reels use a simpler single-step flow (no container polling needed).' This goes beyond the schema and annotations by clarifying prerequisites and the absence of a container-checking step.

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 concise and well-structured: it leads with the purpose, then lists prerequisites, arguments, return value, and notes. Each section is brief and contributes meaning. The note about the single-step flow is a useful distinction. There is little redundancy, though the Args list repeats the schema's parameter names and descriptions.

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 straightforward publish tool with no output schema, the description covers the essential operational aspects: prerequisite calls, required parameters, return type (reel/video ID), and specific notes about video hosting and flow. It does not elaborate on error handling or rate limits, but these are not critical for a single-step publish. The optional response_format parameter is documented in the schema, so no gap exists there.

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 schema covers all 5 parameters with descriptions (100% coverage). The description lists the parameters and repeats their meanings without adding new semantic details (e.g., formats, constraints, examples). It does note the prerequisite 'meta_list_pages' which is a global dependency, not per-parameter. Since the description adds minimal value over the schema, a baseline 3 is appropriate.

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 clearly states the action ('Publishes') and resource ('a Reel (short-form video) to a Facebook Page'), and explicitly distinguishes it from other publishing tools by mentioning the 'simpler single-step flow (no container polling needed)'. This differentiates it from siblings like meta_create_video_post or meta_publish_page_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?

It provides a clear prerequisite: 'Requires: meta_list_pages must be called first to load page tokens.' This gives necessary context for use, but it does not explicitly state when not to use it or name alternatives. However, the focus on Reels and the single-step note makes the intended usage clear enough.

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