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

Annotations already declare readOnly=false, destructive=false, idempotent=false and openWorld=true, covering the safety profile. The description adds 'defaults to draft status,' but that same default is already stated in the status property description, so it adds little beyond structured data; permissions and side effects remain unstated.

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, front-loaded sentences with no filler: purpose first, then the behavioral default, then the discovery prerequisite. Every sentence earns its place.

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 an 8-parameter mutation tool with a nested meta object, 88% schema coverage and annotations covering the safety profile leave little the description must shoulder. It routes the agent to wp_list_post_types for the required rest_base, but omits permission/auth needs for a write operation.

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 description coverage is 88% (high), so the schema carries the parameter semantics, establishing a baseline of 3. The description adds no syntax, format, or meta-object details beyond what the schema already documents.

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 ('Create a new item') scoped to 'any custom post type,' which implicitly separates it from wp_create_post and wp_create_page. However, it never names the sibling it complements, so the distinction is left for the agent to infer from 'custom post type.'

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?

It gives one actionable prerequisite ('Use wp_list_post_types to discover available post types'), which is genuinely helpful for supplying rest_base. But it says nothing about when to choose this over wp_create_post/wp_create_page or any exclusions, so tool selection remains implied rather than guided.

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