get_customer

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

Annotations already declare readOnlyHint and openWorldHint, which signal a safe read operation. The description adds valuable behavioral context beyond annotations: 'Cards are never returned' and 'Requires CUSTOMERS_R', which inform the agent about data exclusion and permission requirements. This is a meaningful addition beyond the structured metadata.

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 three sentences of minimal length, front-loaded with the primary purpose, and every sentence adds specific information: purpose, parameter usage, and constraints. No wasted words.

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 two-parameter get-by-ID tool with an output schema present, the description covers the purpose, parameter usage, data exclusions, and authorization requirement. It is sufficiently complete for an agent to correctly select and invoke the tool without needing additional clarification.

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 input schema has no descriptions for either parameter (0% coverage), so the description must compensate. It clarifies customer_id's purpose implicitly via the tool's purpose, and explicitly explains include with concrete examples ('include=["addresses"] or include=["orders"]') and the concept of opting into optional fields. This adds useful meaning beyond the raw schema.

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 opens with 'Return a single customer by ID,' a specific verb+resource+scope statement that clearly distinguishes this from list/search tools. It unambiguously identifies the operation and the key identifier.

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 provides clear context on when to use the tool: when you have a customer ID and want a single customer. It also gives usage details like the include parameter for optional fields and the required CUSTOMERS_R permission, but it does not explicitly name alternative tools or state when not to use it.

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