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

Annotations already cover the safety profile (readOnlyHint, non-destructive), but the description adds real value by disclosing the scope boundary ('Does not include menu items'), the version requirement, and the runtime behaviour ('runs straight away' with no approval step). The closing sentence restates the read-only annotation somewhat, which keeps this from a 5.

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 and return shape, then the sibling cross-references. The final sentence about 'Through Royally' is slightly redundant with the readOnlyHint annotation, but overall the text is tight with no filler.

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 compensates by enumerating returned fields, and it closes the obvious ambiguity about menu items, adds a version gate, and names the discovery alternative. An agent has everything needed to call this correctly.

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 100%, so both menu_id and site_id are already documented in the schema. The description adds only the implicit point that the identifier is an ID rather than a slug, which is minor. Baseline 3 applies where the schema does the heavy lifting.

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 WordPress navigation menu by ID') plus the exact shape of the returned record. It is immediately distinguishable from the sibling listing tools wp_list_menus and wp_list_menu_items.

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?

Explicitly routes the agent: use wp_list_menu_items with the same id for items, and wp_list_menus first if only a name/slug is known. It also states a prerequisite (WordPress 5.9+), which is exactly the kind of when-to-use context most definitions omit.

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