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

Annotations already declare non-readOnly/non-idempotent/non-destructive, so the safety bar is lower. The description still adds non-obvious behavior: every write path performs this automatically, so the call is normally redundant, and it explicitly bounds its scope to WordPress-internal caches. That prevents both unnecessary calls and false expectations.

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?

Two sentences, zero filler: the action is front-loaded, then the trigger and the scope limitation follow. Every clause earns its place and nothing is repeated from the annotations.

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?

A single-parameter, no-output-schema cache-buster needs exactly the trigger, the failure signature, and the scope boundary — all present. Nothing an agent needs in order to decide whether to call it 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?

Only one parameter (site_id) and schema description coverage is 100%, so the schema fully documents it. The description adds no syntax or format meaning beyond that, which is the expected baseline when the schema carries the load.

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 ('Clear Elementor's CSS cache and bump the versioned per-post CSS files') and is unmistakably distinct from the many wp_* write/structure siblings. An agent can tell exactly what this does without opening the 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?

Gives an explicit trigger ('only when a change you can confirm landed in the data is still not visible'), names the concrete failure mode to look for (stale post-<id>.css from CDN/host cache), and states the negative case ('does NOT purge caches outside WordPress; if it does not help, the cache is at the CDN'). This is a textbook when/when-not.

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