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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds valuable behavioral context beyond annotations: customer name and email are partially redacted, and order history is capped at the most recent 200 orders. No contradiction with annotations.

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 concise sentences with zero fluff. The core action is front-loaded, followed by output scope and identifier provenance, and each sentence contributes distinct information.

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 single-parameter, read-only tool with a rich output schema and comprehensive annotations, the description fully covers redaction, the 200-order cap, and identifier provenance. Nothing essential for correct invocation 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 covers the only parameter (customer_id) at 100%, giving the source as 'from list_customers.' The description reinforces this by saying the id comes from the customer lifetime value list, but that's a minor addition rather than substantive semantic enrichment. 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 uses a specific verb ('Get') and resource ('lifetime value detail for a single customer'), and enumerates the exact fields returned: net profit, revenue, revenue, CAC, tenure, and order history. This clearly differentiates it from aggregate siblings like get_ltv_summary and direct list tools like list_customers.

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?

It provides clear context: the tool is for a single customer and requires the customer id from the customer lifetime value list. However, it doesn't explicitly name alternatives or state when not to use this tool, so it falls just short of full exclusionary guidance.

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