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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: captions arrive ready to paste with {link} filled in, media come in posting order, and the due time is included — so the agent knows what the payload looks like and that this is a hand-off-to-a-human list.

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?

Three dense sentences with no filler; the scoping statement leads and the sibling reference and parameter note follow. Slightly compressed in places but every sentence carries 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?

An output schema exists so return values need not be fully spelled out, yet the description still conveys the key payload features (caption, media order, due time). Combined with the until explanation and the mark_posted hand-off, an agent has enough to call and use it correctly.

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 50%: brand is documented in the schema, while until is undocumented there. The description compensates by explaining until as an ISO time that also surfaces tasks coming due before then, closing the gap. brand is left to the schema, which is acceptable since it is described there.

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 resource and scope: approved manual targets that are due now or overdue and need platform action. It defines what a 'manual task' is (a person must post by hand), which distinguishes it from the automated posting siblings. It does not explicitly contrast with other list tools (list_posts, show_posts), but the scope is unambiguous.

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 'due now or overdue' and 'need action on the platform' framing makes the trigger condition clear, and it names mark_posted as the follow-up once the person has posted. No explicit when-not guidance, but the context is sufficient to select the tool correctly.

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