count_customers

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

No annotations are provided, so the description carries the full burden of disclosing behavior. It states 'Count total customers' and 'optionally filtered by creation date,' but it does not explicitly say what it returns (e.g., an integer count), nor does it mention any edge cases such as whether deleted customers are included or how date boundaries are handled. For a read-only count, this is a notable gap in return-value clarity.

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 a single, concise sentence that front-loads the core purpose and includes the key optional filter. Every word contributes value; no fluff or redundant phrasing.

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?

This is a simple tool with two optional parameters, full schema coverage, and no output schema or annotations. The description covers the purpose and filter, but lacks an explicit statement about the return value (e.g., 'Returns the total number of customers'). Given the low complexity, it is adequate but not fully complete.

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% for both parameters (created_on_max and created_on_min), so the schema already documents their meaning. The description does add the context that these filter by 'creation date,' which maps directly to the parameters, but it does not add details beyond the schema. Baseline 3 is appropriate.

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 tool's function: 'Count total customers in the store.' It uses a specific verb ('count') and resource ('customers'), making it distinct from other customer tools like list_customers, get_customer, and search_customers. The optional filter by creation date is also mentioned, adding precision.

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 usage: use when you need a total count of customers, optionally within a date range. However, it does not explicitly compare with alternatives like count_products or count_orders, nor does it provide when-not-to-use guidance. The intended use is fairly obvious from the wording, but no explicit guidance is given.

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