get_customer

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

No annotations are provided, so the description carries the behavioral disclosure burden. It correctly implies this is a read-only fetch operation ('Get details'), which aligns with expected behavior. However, it doesn't add richness like what happens on missing/invalid IDs, whether it returns 404 or errors, or what fields are returned. With zero annotations, a 3 reflects that it's correct but minimal.

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 appropriately brief at two short sentences with a clear 'Args' section documenting the parameter. No wasted words. It's slightly padded with the Args formatting but fundamentally lean.

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?

Despite zero annotations, the tool has a single simple parameter and an output schema, so the description is adequate. The key domain knowledge (human-readable ID vs GUID) is captured. For a simple get-by-ID tool with an output schema covering return shape, this is essentially complete - missing only guidance about error/not-found behavior.

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 coverage is 0% so the description must compensate, and it does meaningfully. It clarifies that 'id' is the human-readable GnuCash ID (e.g., '000001'), NOT the internal GUID - which is critical domain knowledge that prevents the agent from passing the wrong identifier. This is real value added beyond the bare 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 clearly states the verb+resource: 'Get details for a specific customer by ID.' It distinguishes from siblings by targeting a single customer retrieval (as opposed to list_customers which lists all, and create_customer/update_customer/delete_customer which are CRUD operations). The scope is precise and unambiguous.

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 (when you need a single customer's details) and contrasts implicitly with list_customers, but it doesn't explicitly state 'use list_customers when you need to enumerate customers' or provide exclusions. No explicit when-not guidance or named alternatives is given.

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