get_customer_totals

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds that it shows total registered customers and their roles, which is useful output context, but it does not disclose other behavioral traits such as rate limits, data freshness, or performance characteristics. This is adequate but not rich beyond the annotation.

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?

The description is exactly two short sentences, delivering the core purpose without redundant words. It is front-loaded with the action ('Get') and easily skimmable, making it highly concise and well-structured.

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 simple read-only tool with one optional parameter and no output schema, the description adequately explains what the tool does and what it returns (total counts and roles). It does not mention the customizable 'fields' parameter, but the schema covers that, and the tool's simplicity means the description is sufficiently complete for an agent to select and use it correctly.

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?

The schema description covers 100% of the single 'fields' parameter with a clear explanation ('Comma-separated fields to return (default: slug,name,total)'). The tool description adds no additional parameter semantics, so the baseline score 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?

The description uses the specific verb 'Get' with the resource 'customer counts' and a clear grouping dimension ('by WordPress role'). This distinguishes it from sibling tools like get_order_totals or list_customers, making the purpose unambiguous.

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?

The description implies a clear use case (aggregate customer counts by role) but does not explicitly state when to use this tool over alternatives like get_customer or list_customers. It also lacks any exclusions or explicit 'when-to-use' guidance, so usage is only implicitly conveyed.

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