Schedule post

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

The annotations already declare this is a mutating, destructive, idempotent, open-world operation. The description adds valuable context beyond that: pre-publish checks can block the call, missing titles or empty bodies stop scheduling, scheduled posts remain editable until publication, and section fallback behavior is explained.

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 front-loaded and well structured, moving from the core action to constraints and fallback behavior. The first two sentences are slightly redundant, but the overall text is efficient and every remaining sentence carries useful 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?

For a four-parameter scheduling mutation with annotations and full schema coverage, the description is nearly complete. It covers constraints, failure conditions, editability, and audience routing; only the expected return or confirmation behavior is not described, which is a minor gap given the absence of an output schema.

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 100%, so all four parameters are already documented in the schema. The description reinforces key semantics such as time zone, future time, email default, and section fallback, but does not add much beyond the schema's own descriptions.

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: scheduling a draft to publish at a future time. It also clarifies the channels (web and email) and audience behavior, making the tool's purpose immediately clear and distinct from generic publishing.

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 clear conditions for use: the time must include a time zone and be in the future, and the draft must pass Substack's pre-publish check. However, it does not explicitly contrast this with siblings like publish_post for immediate publishing or cancel_scheduled_post for cancellation.

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