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

Adds context annotations cannot carry: the exact returned field set, the fact that register_rest_field extensions (e.g. ACF) are silently discarded, and a nuanced permissions caveat — the tool is exposed as read for all callers yet WordPress enforces edit-level or custom capabilities per CPT, so low-privilege callers may still hit errors.

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?

Dense and front-loaded: identity, required params, return shape, limitations, alternatives, then permission caveat. The final sentence about the Royally server marking it read-only largely restates the readOnlyHint annotation and could be dropped.

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?

No output schema exists, yet the description enumerates the returned fields and explicitly names what is absent (custom REST fields/ACF), plus the permission behavior. Nothing material an agent needs to call it correctly is missing.

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 100%, so the baseline is 3; the description goes slightly beyond by stating that rest_base may be either the CPT rest_base or its post_type slug and by pointing at wp_get_post_types to discover it, saving a discovery round-trip.

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 ('Gets a single custom post type (CPT) item by REST base + item ID') and explicitly separates itself from wp_get_post / wp_get_page by naming them as the built-in alternatives.

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?

Clear routing rules: use wp_get_post / wp_get_page for built-in post types, and use wp_get_post_types to find the rest_base. It does not address when to prefer wp_list_cpt_items or when a REST call (wp_rest_read) would be better, so it falls short of full alternatives coverage.

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