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

Annotations already flag this as a destructive, open-world write, and the description adds genuine behavioral context beyond them: it explains the state transitions and, importantly, the timezone semantics ('Without an offset the time is the organization's local time'). It does not mention permissions or rate limits, keeping it short of 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 tightly written sentences, front-loaded with the core action and followed by the state-transition and timezone details. No filler; every clause 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 mutating tool with no output schema but strong annotations, the description covers the key state behavior and timezone pitfall. It leaves permission/auth requirements unstated, but otherwise gives an agent enough to invoke it correctly.

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 67% (scheduledFor and idempotencyKey documented, postId not). The description adds meaning the schema lacks by defining the timezone behavior for the scheduledFor value when no offset is present, which is real semantic value beyond the bare 'ISO 8601' note.

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 precise verb and resource ('Set the date and time of an existing post') and clarifies the two state transitions it performs: an already-scheduled post is moved, while a DRAFT or failed post becomes scheduled. This clearly separates it from siblings like update_post or unschedule_post.

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 implies when the tool applies through its scenario framing (rescheduling a scheduled post, scheduling a draft/failed one), but it never explicitly names an alternative such as unschedule_post or retry_post, nor states prerequisites like required account ownership. Usage is inferable but not spelled out.

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