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

Annotations already declare destructiveHint=true, openWorldHint=true, and idempotentHint=false, so the safety profile is covered. The description adds real context: the ~5 minute posting window, calendar visibility, the precondition that the short must be exported, and that the returned schedule_id is not a final outcome. It doesn't spell out what 'destructive' practically means (e.g. cannot be un-posted once live), but it's meaningfully richer than the annotations.

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?

Four tight sentences, front-loaded with the action and targets, then timing, preconditions, and return/follow-up. No filler, though the calendar mention is the least load-bearing clause.

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 nested-object mutation tool with no output schema, the description covers the critical gaps an agent needs: what happens on success (schedule_id), how to verify or undo, the export precondition, and timing semantics. Nothing essential to calling it correctly is missing.

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?

Top-level schema coverage is 50%, but nested properties (caption, privacy_level, draft, tags, title) are individually documented in the schema. The description adds meaning the schema cannot: tiktok/youtube are alternative-or-both targets, publish_at omitted means immediate posting, and past timestamps are rejected. That compensates for the coverage gap.

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 (schedule) plus resource (an exported short) and the target platforms, which cleanly distinguishes it from schedule_slideshow and clip_video among the siblings. An agent knows immediately what this does without opening the schema.

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?

Explains the targeting choice ('Set tiktok, youtube, or both') and the publish_at timing behavior, and names follow-up alternatives (list_scheduled_posts to check, cancel_scheduled_post to undo). It lacks an explicit 'use schedule_slideshow instead for slideshows' routing line, but the context is clear.

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