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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description still adds value beyond them by enumerating the returned fields (id, name, slug, count, locations) and noting it 'runs straight away' with no confirmation step, though it says nothing about pagination or menu counts on large sites.

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 return shape, then the sibling pointer, then the site/read-only note — three short sentences with no filler. The trailing annotations duplicate structured data slightly but cost almost nothing.

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?

There is no output schema, and the description compensates by listing the returned fields, so an agent knows exactly what a call yields. For a zero-required-parameter read tool, nothing needed to invoke 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% and the single parameter (site_id) is fully documented with its enum value and URL, so the schema carries the load. The description's '(site: demo.royalplugins.com)' merely restates the enum value rather than adding new meaning, which is the baseline 3 case.

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 ('List all registered navigation menus (nav_menu taxonomy)') and even names the underlying taxonomy, which pins down the exact scope. It then distinguishes itself from the items-listing sibling, so an agent can separate the two without opening either 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?

Explicitly routes the agent to wp_get_menu_items when the goal is enumerating items inside a specific menu, which is the main adjacent task. It lacks an explicit 'when not to use / prerequisites' statement, but for a parameterless read the context is clear enough.

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