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

Annotations already declare destructive/openWorld/idempotent, and the description goes well beyond them: it discloses two distinct execution paths (in-place vs. rebooked at the same slot with a new postId), the status strings returned ("rebooked", "labeled", "unchanged"), the 5-minute refusal window, per-month plan quota consumption, and that changes hit real accounts. It is consistent with destructiveHint=true and idempotentHint=true.

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 most consequential facts — what is mutated, permission/plan requirements — are front-loaded in the first sentence, and the backtick-quoted parameter names make it scannable. It is still a single very dense paragraph with parenthetical asides and some redundancy against the schema, but little of it is genuinely wasted.

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 10-parameter, nested-object mutation with no output schema, the description covers everything an agent needs: permissions, plan/quota consequences, the rebook-vs-in-place outcome, return status values, refusal windows, and the confirmation requirement. Nothing material about calling it correctly is left unstated.

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?

The input schema is fully documented at 100% coverage, so the baseline applies. The description restates the salient parameters (text/platformText, firstComment, applyAutoFirstComment, removePlatforms, labels) and adds a useful orientation — e.g. that firstComment is per-platform and X/Bluesky have none — but most of that detail is already in the schema text and it omits scheduledAt, labelMode, and instanceLabels entirely.

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 opening clause names a specific verb and object — "CHANGES WHAT A SCHEDULED POST WILL PUBLISH on real accounts" — and immediately delimits what is preserved (slot, accounts, options, labels, draft), which cleanly separates it from reschedule_post, cancel_scheduled_post, and edit_post_labels. The title reinforces it with the three editable areas.

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?

Gives clear operative context: it is for editing a scheduled post (not a published one), it is refused within 5 minutes of the slot, requires `publish` scope and Pro plan, and repeating an edit is a no-op. It also instructs to confirm new text with the user first. It never names sibling alternatives (e.g. use reschedule_post to move time, or DELETE to remove all platforms), so the routing guidance is contextual rather than exclusionary.

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