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

Annotations already declare non-destructive and idempotent, and the description adds genuinely new behavior: content is untouched, pages re-cache naturally on visitor load, there is nothing to undo, and it executes immediately. It also discloses the response payload — each site's cache plugin plus a list of sites with none.

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 the action and scope, then plugin order, then parameter default, then safety/return behavior. Every clause carries information; nothing is repeated from the title or schema.

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 covers the reply shape, and for a one-optional-parameter mutation it covers safety, reversibility, batching limits, and plugin fallback. An agent has everything needed to call it and interpret the result.

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%, so site_ids is already documented, but the description adds two facts the schema lacks: the omit-default of every connected site and the 50-site cap on a single call. That is meaningful added semantics beyond the structured field.

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 the page cache') plus the exact scope ('on each chosen site') and the plugin precedence order (ForgeCache → LiteSpeed → W3 Total Cache). No sibling tool performs cache purging, and the definition makes that scope unmistakable.

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 clear operating context: the default is every connected site when site_ids is omitted, and the batch is capped at 50. It does not name any when-not-to-use conditions (e.g., mid-deploy or during a maintenance window), but with no comparable sibling the routing risk is low.

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