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

With no annotations, the description carries the full behavior burden and does: it discloses that nothing is applied immediately, that activation is a one-click admin action, that the plugin auto-disables if it fatals on first load, and that re-activation must be idempotent thanks to guards. These are non-obvious safety traits an agent could not infer from the schema.

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 core action and the 'you do not change the site' constraint, then the plan gate, then code requirements — a sensible ordering. Slight redundancy: the guard requirement is stated twice ('guarded ... so re-activation is safe' and 'starting with <?php, guarded'), which costs a little density.

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?

For a mutation-adjacent, no-annotation tool with no output schema, the description covers activation model, permission/plan gating, failure semantics, idempotency, and payload constraints — everything needed to call it correctly. No dependency on undefined return values.

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 baseline is 3; the description still adds meaning by requiring that 'code' be a complete, self-contained mu-plugin starting with <?php and guarded with function_exists/class_exists checks — constraints the schema states more tersely. It says nothing extra about run_id, rollback, or title beyond the schema text.

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?

The first sentence states a precise verb and artifact: draft an ACTIVATABLE fix (mu-plugin PHP + reason + rollback) for a site, explicitly not applying it. The contrast with siblings that mutate or diagnose (scan_site, draft_report) is made explicit by 'You do NOT change the site'.

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?

It names the gating condition (PAID plans only), the failure mode ('plan_required'), and the exact fallback action ('just explain the fix in text instead') so the agent knows what to do when refused. The handoff model — agent drafts, owner activates — is stated up front.

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