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

With no annotations, the description carries the burden and does disclose real behavior: the draft must pre-exist, mid-publish posts are rejected, and attach_automation is left OFF by default with the user enabling it in the scheduler. It stops short of stating permission/account requirements or the success response, but the state preconditions and default-off semantics are genuinely non-obvious.

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?

Dense but front-loaded: identity of the tool, the disambiguation rules, then the optional automation caveat. The quoted user-phrase examples earn their place by clarifying scheduledAt format, though the definition sits at the long end of what is needed.

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?

No output schema and no annotations, with nested objects and a 0%-documented schema, so the description does more work than most. It covers purpose, routing, preconditions and the automation default, but omits return values, timezone semantics, and the entire attach_funnel parameter.

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 0%, so the description must compensate. It clarifies postId/postName ('its caption / opening words'), scheduledAt (free-text like 'tomorrow 9am' or ISO, never look it up first), and attach_automation's one-of variants (template_id / prompt / keyword+link). It says nothing about timezone or attach_funnel, leaving two parameters undocumented in both schema and description.

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+resource ('Put an EXISTING draft on the publishing calendar') and immediately distinguishes itself from the two nearest siblings, create_scheduled_post and update_scheduled_post, by naming the conditions that select each. An agent can route correctly without opening any 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?

Explicit when-to-use ('draft is already in hand'), when-not ('Supplied CONTENT with no draft ⇒ create_scheduled_post', 'Moving an ALREADY-scheduled post ⇒ update_scheduled_post'), plus a hard precondition ('Rejects a post mid-publish'). Alternatives and their selecting conditions are all named.

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