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

Annotations declare readOnlyHint/idempotent/non-destructive, and the description is consistent with them while adding real behavioral context: it never publishes or schedules on its own, opens no public link, and what to do if the tool is unavailable (refresh connection metadata). This resolves the apparent tension between a read-only hint and a UI that offers scheduling.

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?

Five short sentences, front-loaded with the usage trigger before the mechanics and the negative scoping statements. Dense but each sentence does work; the fallback sentence is the most peripheral yet still useful for error recovery.

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 needn't be described. The description covers prerequisites, visual rendering behavior, what it does not do (publish/schedule/public link), and the degraded-client path — enough for an agent to invoke it correctly in this 30-tool sibling set.

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% for the single postId parameter, so the description must carry the load; it does by telling the agent where the value comes from ('pass the found post ID as postId' from search_posts/search_post_drafts). It does not clarify format expectations beyond the schema's 1-128 char string, which is a minor gap.

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 action (render the post card UI inside chat) with its scope (preview, text editing, scheduling), and explicitly distinguishes itself from lookalikes: 'A screenshot or preview_post URL is not this UI.' An agent can separate it from preview_post, get_post, and update_post 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?

Names the triggering condition ('when the author asks to show a post card inside the chat or choose publication controls there') and the required upstream step ('After search_posts or search_post_drafts, pass the found post ID as postId'). It also gives a fallback path for clients without UI support.

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