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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint: false, and the description adds behavioral context by stating the classification basis (lifetime spend and order count) and the tier taxonomy. It does not contradict the annotations and gives an agent confidence that this is a safe, side-effect-free classification operation.

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 states the action, the resource, the criteria, and the output categories with no filler or redundancy. It earns its place and is immediately scannable for an agent.

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 classifier with optional params and an output schema, the description is largely complete: the schema covers parameters, and annotations cover safety. Slight room for improvement is that the exact distinction between tiers and the role of order count could be clarified, but nothing required for a basic call is missing.

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% and each of the three optional parameters is already described with ranges and defaults, so the schema carries the documentation burden. The description adds only the high-level criteria ('lifetime spend and order count') without adding parameter-level detail beyond what the schema already provides.

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 a specific verb ('Classify') with a clear resource ('customers') and names the exact output categories (VIP / regular / casual / one-time), so an agent knows immediately what the tool produces and can tell it apart from sibling reporting 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 implies when to use it: whenever customer spend-tier classification is needed. However, it offers no explicit when-to-use guidance, no exclusion conditions, and does not contrast with similar sibling tools such as run_win_back_candidates or get_ltv_summary, so the agent must infer the intended context on its own.

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