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

Annotations already declare non-readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds real behavioral value by enumerating valid state transitions, which tells the agent the legal state machine. It does not, however, restate the idempotency implication (re-applying the same status is a no-op) that the annotation implies.

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 tight sentences, front-loaded with the core action and immediately followed by the domain-specific transition guidance and the sibling routing note. No filler.

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 tool with no output schema, the description plus annotations cover scope, valid transitions, and the alternative tool, which is sufficient to invoke correctly. The only minor gap is that it references a 'woo_update_order' tool that does not appear in the sibling list, a potential routing ambiguity.

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 the baseline is 3, and the description goes beyond the schema's bare enum by specifying which status transitions are common, adding semantic guidance about the 'status' argument. It does not clarify the optional 'site_id' targeting, but the schema already documents it.

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+resource ('Update the status of a WooCommerce order') and explicitly carves out what it does not cover by routing to 'woo_update_order' for other fields. An agent can distinguish this status-only tool from a general order update 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?

Provides concrete when-to-use context via the common transition list (pending→processing, processing→completed, any→on-hold, any→cancelled) and names the alternative tool for the out-of-scope case. Both the use case and the exclusion are explicit.

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