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

The description is exceptionally transparent about behaviors beyond the annotations. It explicitly states that the tool is dry by default (does not queue or spend), that passing dryRun:false actually queues to real public accounts, and that captions are screened against brand voice rules with possible drops. It also notes the plan can return shorter than expected with reason in notes. This fully discloses side effects and conditional behavior, complementing the sparse annotations without contradiction.

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 a single block but well-structured, front-loading the core action and then explaining the dry-run behavior, warning, and screening process. Each sentence adds necessary context; nothing is redundant. It is slightly longer than necessary, but every clause serves a purpose (safety, behavior, edge cases), so it earns a 4 rather than a 5 for perfect conciseness.

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?

Given there is no output schema, the description fully explains the return value: 'the exact posts it WOULD queue — the caption, the creative, the channels and the per-channel visibility.' It also covers the scenario of dropped posts due to voice rules and notes the reason. It covers the dry-run default, the safety warning, and the stored dryRun interaction. This is comprehensive for a tool with only two parameters and no nested objects.

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?

Both parameters are already well described in the schema (100% coverage). The description adds extra value by explaining the interaction between force and dryRun in the force parameter's own description ('Combined with dryRun:false it still respects a stored dryRun'). This clarifies a subtle behavior not obvious from the schema alone. Since schema coverage is high, the baseline is 3, but the added interaction nuance raises it to 4.

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 clearly states the action: 'Run the refill NOW instead of waiting for its daily turn.' It uses a specific verb (run) and resource (posting refill), and distinguishes itself from waiting for the scheduled turn. It implicitly differentiates from related sibling tools like set_post_refill or backfill_posts by emphasizing immediate execution vs. configuration or bulk backfill.

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?

The description gives strong procedural guidance: 'SHOW THE PREVIEW TO THE USER BEFORE EVER PASSING dryRun:false' and explains the dry-run default. It also implies when to use it (when you want to bypass the daily schedule). However, it does not explicitly list alternative tools or conditions when this should not be used, so it falls short of a 5.

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