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

Annotations only say this is a non-read-only, open-world, non-idempotent write; the description adds substantial context beyond that: no credit cost, an admin must enable MCP publishing, a 2-minute dedupe window keyed on requestId, refusal when a requestId is reused with different arguments, and a hard failure when the creative's aspect ratio does not fit the format with resize_creative as the remedy. These are exactly the operational traits an agent cannot get from the annotations.

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 core action and the immediate-vs-scheduled rule are front-loaded, and essentially every sentence carries non-redundant information. It is dense, however, with several independent rules packed into long sentences, so an agent must parse carefully rather than skim a short list.

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 an 8-parameter, open-world write with real side effects, the description covers preconditions (admin allowance), input sourcing, scheduling semantics, retry/idempotency behavior, format selection, caption rules and a concrete failure mode. An output schema exists, so the absence of return-value explanation is not a gap.

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 100%, so the baseline would be 3, but the description adds genuine meaning: scheduledAt must be a future ISO 8601 timestamp carrying its offset (with worked examples), format is normally inferred from channel + creative and should only be passed to override, and caption is mandatory for every format except a story. It does not restate requestId's schema text in more depth than the schema already does, which keeps it below a 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?

States a specific verb and resource ('Post one of the brand's creatives to a connected channel, publicly') and immediately separates immediate vs scheduled publishing. It explicitly carves out TikTok to prepare_tiktok_post, so an agent can distinguish it from submit_tiktok_post, cancel_publication and list_publications without opening a 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?

Gives explicit when-not guidance ('Not for TikTok... call prepare_tiktok_post'), a user-confirmation requirement before calling, and the decision rule between connectionId and platform. It also names the upstream tools that supply each argument (list_integrations, get_workspace, list_creatives), leaving little to inference.

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