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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation/risk profile is covered. The description adds one genuinely useful precondition — the content must not have posted yet — but says nothing about permissions, partial-vs-full replacement of caption/hashtags, or error behavior when the publish already went out.

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?

A single tight sentence with the scope condition front-loaded; nothing is wasted. It is arguably too terse rather than padded, but sizing itself is appropriate.

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 a mutation tool with no output schema and zero parameter descriptions, the description covers the core intent and the unposted precondition but omits prerequisites, what a successful response contains, and the identity of the required publishId. Adequate but with clear gaps.

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 description coverage is 0% for 3 parameters, so the description has to compensate. It identifies two of the three mutable inputs (caption, hashtags) but leaves publishId unexplained and gives no constraints (2200-char caption, 30-hashtag cap) that the schema supplies only structurally.

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?

Specific verb (update) plus resource (scheduled content publish) and the exact mutable fields (caption, hashtags). It distinguishes itself from update_content_piece and update_content_source by naming the publish entity, though it doesn't call out those siblings explicitly.

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 phrase 'content that has not posted yet' implies a when-to-use condition and an implicit when-not (already-published content), but no alternative tool (cancel_content_publish, get_content_publish) is named for the posted case. Usage context is implied rather than spelled out.

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