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

The description adds meaningful behavior beyond the annotations: posts fire sequentially, times display in the customer's local timezone, and Allow posting permission is required. These are useful operational details that annotations do not convey, and there is no contradiction with the write/destructive flags.

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 compact and front-loaded: the primary purpose appears first, followed by behavior, permission, and routing guidance. Every sentence adds value without repeating schema or annotation information.

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?

The description covers purpose, permission, platform values, timing semantics, and alternatives. An output schema exists, so return values need not be explained. Minor gaps remain around run_id and captions semantics, but sibling tools like get_run and the schema shapes mostly compensate.

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 description coverage is 0%, so the description must compensate. It clarifies scheduled_at as ISO-8601, lists acceptable platforms, and hints at timezone behavior, but it leaves run_id and captions with no semantic explanation, and the timezone parameter is only implied rather than explicitly described.

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 states a specific verb and resource: 'Schedule a finished run to post at scheduled_at (ISO-8601)'. It also explicitly distinguishes from siblings by saying 'Prefer this over post_run' and referencing create_campaign's alternative, so an agent can tell this tool apart without opening schemas.

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 gives explicit when-to-use guidance: 'Prefer this over post_run when the user names a time' and notes that create_campaign can accept scheduled_at instead. It also states a prerequisite, 'Requires Allow posting', which is actionable selection context.

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