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

Goes well beyond the annotations: it discloses that saved_fields is read back from the DB so silent-drop/silent-modify is surfaced, that backslashes and JSON-escapes survive verbatim, and — critically — that on this deployment the call is queued for human approval and nothing changes on the site until then. That approval-gating disclosure materially changes how an agent must interpret the destructiveHint=true result, which annotations alone cannot convey.

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?

Front-loaded with purpose, then the highest-value caveats (readback verification, date semantics, escaping, approval gate) in a compact sequence. The site tag and the Royally sentence are dense but each earns its place; minor run-on phrasing in the backslash sentence is the only drag.

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?

With 14 parameters and no output schema, the description compensates by describing the response shape (saved_fields) and the async approval semantics — the two things that would otherwise blindside an agent. Only small gaps remain: it doesn't say what happens to unspecified fields or how the pending-approval handle is returned.

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 71%, so most parameters are documented in the schema; the description still adds meaning beyond it by explaining date's two modes, the DB-readback verification behavior, and backslash/escape preservation for content. It does not enumerate the other mutables (status, title, author, comment_status), but the schema handles those adequately, so this exceeds baseline.

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 and resource ('Update existing post') and immediately scopes it ('any post type'), which tells an agent this covers pages/CPTs too, distinguishing it from the narrower wp_update_page sibling. The agent knows exactly what will be mutated without opening the 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?

Gives one concrete usage rule ('Pass date to reschedule or backdate') and thereby implies when the date parameter is appropriate. However, it never names alternatives (wp_update_page, wp_update_post_meta, wp_update_block_attributes) or states when NOT to use this tool, so routing among the many update_* siblings is left to inference.

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