Count users

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

Annotations declare readOnlyHint and idempotentHint, and the description adds meaningful behavioral detail beyond that: it excludes @severalnines.com / @s9s.io logins in production, includes deleted users, and behaves differently when an admin session is configured (client-side counting with breakdowns). This is transparent about side effects (none) and data scoping.

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 concise, front-loaded with the core purpose ('Count CCX users'), and then provides necessary nuance in two additional sentences. Every sentence adds value, with no redundancy or fluff. It's appropriately sized for the tool's simplicity.

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?

Given the tool has no parameters, no output schema, and simple functionality, the description covers the key behavior: what is counted, exclusions, and the admin-session nuance. It doesn't explicitly state the return format (e.g., a number or object), but it implies counts are returned and can be reconciled. For a count tool, this is adequate.

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 tool has 0 parameters, and the schema description coverage is trivially 100%. Per the calibration rules, a baseline of 4 is appropriate for zero-parameter tools. The description doesn't need to explain parameters since none exist, and it doesn't introduce confusion.

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 clearly states the action ('Count') and resource ('CCX users'), and distinguishes itself from siblings by explaining the specific endpoint and its behavior (excluding certain domains, including deleted users). This is a specific verb+resource with scope, making it easy for an agent to differentiate from list or management tools.

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 explains when the tool is appropriate: it counts customer accounts and notes the nuance of the counter endpoint versus client-side counting when an admin session is configured. While it doesn't explicitly name alternatives, the context makes clear this is for counting rather than listing or modifying, and the reconciliation note suggests usage for verification.

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