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

Goes well beyond annotations by disclosing three behavioral facts the agent could not otherwise know: all values of the key are removed, the response returns an undo token that can restore them, and execution is queued behind human approval so the site is unchanged until then. This directly complements destructiveHint=true with real consequences and a recovery path.

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?

Three short sentences, with the destructive scope and the undo affordance front-loaded. The inline '(site: demo.royalplugins.com)' is minor clutter that duplicates the site_id enum description, but nothing else is 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?

With no output schema, the description correctly tells the agent the reply carries an undo token, and it covers the approval workflow, so the agent knows the call is not synchronous in effect. Remaining gaps: no mention of behavior when the key does not exist and no clarification of post_id scope.

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 only 33% (only site_id is documented), so the description should compensate more. It does convey that 'key' identifies all values to be deleted, but says nothing about post_id semantics (e.g., whether it must be a post, page, or any post type) or what happens if the key is absent.

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 (delete post meta) plus the crucial scope detail 'every value of the key', which distinguishes it from wp_update_post_meta and wp_add_post_meta. An agent can tell exactly what gets removed 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?

The description clarifies the operational context (Royally approval gate, nothing changes until a person approves), which affects when/how the call is made. However, it never states when to prefer this over siblings such as wp_update_post_meta (to change a value) or wp_delete_term_meta, leaving alternative selection to inference.

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