Show available updates

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description still adds substantive behavior: results are cached rather than fetched, no remote request is made, and the cache refreshes roughly twice daily. It also discloses the capability requirement ('Needs update_core'), which annotations cannot express.

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 dense sentences, front-loaded with the verb and resource, then the caching caveat, then the return shape. Every sentence carries information an agent would otherwise have to guess.

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 supplies the exact return structure (core object, plugins and themes arrays with their field names) and explains that empty lists mean no known update rather than a failed check. Nothing needed to call this correctly or interpret its result 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly spends no space on parameters and instead documents the return shape.

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 ('Report available core, plugin and theme updates') and immediately scopes it to WordPress's own last scheduled check, which separates it from sibling inventory tools like wp_list_plugins and wp_list_themes that list installed items rather than pending updates.

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 parenthetical 'read-only, cached data; triggers no remote request' plus 'WordPress repeats that check on its own, about twice a day' tells an agent exactly when this tool is appropriate and when its data is too stale to act on. It stops short of naming an alternative path for forcing a fresh check, so no explicit when-not routing is given.

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