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

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=false, so the safety profile is largely covered. The description adds the useful human-in-the-loop confirmation requirement and clarifies that only 'expired' transients are removed, but says nothing about what happens to non-expired data, permissions required, or the scale of deletion.

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 short sentences with zero filler; the destructive action is front-loaded and the safety precondition follows immediately. Every sentence earns its place.

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 only two fully documented parameters, rich annotations, and no output schema, the definition covers what an agent needs to call it safely. Minor gap: no mention of the result (e.g., count of deleted transients) or of prerequisites such as site connectivity.

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%, and the schema already explains both site_id (use list_sites, not a URL or post ID) and confirm (only after explicit user confirmation). The description reinforces the confirm requirement but adds no new meaning beyond the schema, so the baseline of 3 applies.

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: delete expired WordPress transients, scoped 'across the site'. This distinguishes it reasonably from the broader wc_maint_clear_transients sibling by the word 'expired', though it never names or contrasts that sibling explicitly.

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?

Provides one concrete procedural rule — ask the user for confirmation before calling with confirm=true — which is genuinely actionable. However, it gives no guidance on when to run this versus wc_maint_clear_transients or the other cache-clearing siblings, leaving alternative selection to inference.

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