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

Annotations already declare that this is a non-read-only, non-destructive, closed-world mutation. The description adds meaningful behavior beyond that: drafts are explicitly not published or scheduled, and reusing an Idempotency-Key with the same body returns the original draft rather than duplicating it. It does not discuss permissions or account requirements, but the added idempotency detail is substantive.

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 two tightly written sentences with no redundant framing. The primary behavior is front-loaded, and the second sentence adds the non-obvious idempotency rule without bloating the definition.

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 tool has an output schema and useful annotations, so the description does not need to explain return values or safety metadata. However, with six undocumented parameters and zero schema coverage, the description is only partially complete: it covers the main purpose and idempotency behavior but leaves destination selection and candidate_angle underspecified.

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% across six parameters, so the description must carry the semantic burden. It mentions content, optional media or destinations, and idempotency behavior, but it omits candidate_angle entirely and does not clarify the distinction between suggested_platforms and selected_account_ids, leaving important invocation ambiguity.

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 ('Saves content ... draft') and immediately distinguishes the operation from publishing or scheduling. An agent can tell this is the non-publishing creation path 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?

It clearly establishes the use case as saving a draft rather than publishing or scheduling, which gives useful context against siblings like create_post and publish_post. It does not explicitly name alternatives or say when to use update_draft instead, so it stops short of full routing guidance.

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