Create Reel

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

Annotations already declare readOnlyHint=false, openWorldHint=true and destructiveHint=false, so the agent knows this is an outward-facing write. The description adds genuinely new behavioral context — long runtimes for large videos and that upload progress is streamed to the client — which is exactly the kind of latency signal annotations cannot convey. It omits failure/retry behavior and auth requirements, keeping it below a 5.

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?

Two sentences, both earning their place, with the primary action front-loaded and the latency caveat second. Zero filler or restatement of 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?

An output schema exists, so return values needn't be described, and the description covers the non-obvious operational trait (upload duration). For a 4-parameter write tool with an outward-facing side effect, it could still say more about permissions and what happens when the Page cannot be resolved.

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 coverage is 75%, so most parameters are already documented, and the description adds no syntax or format detail beyond them. The only echo is 'publish (or schedule)', which mirrors scheduled_time without extending it. Baseline 3 is appropriate given the schema does the heavy lifting.

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?

States a specific verb and resource — 'Upload a local video and publish (or schedule) it as a Reel on a Page' — which clearly separates it from create_post and create_photo_post by media type. It stops short of naming those siblings explicitly, so differentiation is inferential rather than stated.

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 phrase 'publish (or schedule)' hints at the immediate-vs-scheduled fork, and the schema's scheduled_time description makes the window explicit. However, there is no guidance on when to choose this over create_post/create_photo_post, nor any stated prerequisites such as Page admin permissions.

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