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

Far beyond the annotations, it discloses cost (20 credits, 402 on low balance, auto-refund on rejection), rate ceiling (max 2 posts/account/day, 409 naming the day), readiness rules (account must be active or delivered/warming up), the 400/409 error semantics, and the lack of server-side retry plus the idempotency-key dedup contract. This is exactly the operational context an agent needs for a destructive, non-idempotent, open-world mutation.

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?

It is a dense single block, but front-loaded with the core action and then ordered by booking, requirements, cost, limits, errors, and retry. Every sentence carries operational weight; the only mild cost is that the paragraph form makes it slightly harder to scan than a bulleted layout would.

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?

With no output schema, the description still explains the return value (status 'scheduled' with scheduledAt on the booked day), and it covers prerequisites, cost/limits, error codes, and retry safety. Nothing an agent needs to invoke this complex mutation 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?

Schema coverage is already 100%, so the baseline is 3, and the description adds real cross-parameter meaning: the caption plus media requirement is satisfied by one of three mutually alternative sources (sourceProjectId, videoUrl, or imageUrls), imageUrls count drives photo vs carousel, and a TikTok carousel gets a curated sound unless musicLink is passed. Some of this (queueFor omission, imageUrls 1/2+) duplicates the schema, so it lands just above baseline rather than a full 5.

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 first sentence states a specific verb and resource ('Queue a post on a hosted / managed account') and immediately scopes it away from anything publish-now, so it is distinguishable from siblings like create_social_post, cancel_social_post, or delete_managed_post. An agent knows exactly what operation this performs 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 gives explicit when-to-use and when-not guidance: hosted accounts have NO publish-now, omit queueFor for the earliest day, and consult get_managed_account_capacity to see availability. It also names the retry protocol (resend with the SAME idempotencyKey) and warns never to call twice for the same content, leaving nothing to inference.

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