get_merchant_lookup

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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly states the return format (JSON string) and the contents (merchant status, revenue total, full chronological timeline), and it clarifies that both app_id and shop_domain are required. It doesn't explicitly note side effects (none expected for a lookup), but the provided details suffice for a read-only 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 efficiently organized with 'Args' and 'Returns' sections. It uses only two short paragraphs and includes an example, with no redundant or filler content. Every sentence adds useful 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?

Given that this is a simple two-parameter lookup with no annotations, the description covers the essential aspects: what it does, required inputs, and the output structure. It lacks explicit usage timing or error/rate-limit caveats, but for a read-only single-merchant lookup, it is largely 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?

The schema provides only parameter names and types. The description enriches both parameters: app_id is explained as 'App GID or numeric ID' and shop_domain is given a concrete example ('my-store.myshopify.com'). This goes beyond the bare string types and clarifies expected input formats.

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 'Get full timeline for a specific merchant', which clearly identifies the action (get) and resource (full timeline for a merchant). It distinguishes from sibling tools by emphasizing a single merchant's chronological events, unlike tools like get_merchants or get_churn_analysis.

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 no explicit guidance on when to use this tool versus alternatives. It doesn't mention when to prefer this over get_merchant_health or get_transactions, nor does it state any exclusions. The only implied context is 'specific merchant', but there is no comparative direction.

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