Карточка клиента

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds meaningful behavioral context beyond those: what exact data is returned (including the 10 orders), accepted identifier formats, and the non-error behavior for non-existent customers (data: null). This fully discloses the operational traits an agent needs.

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 two well-structured sentences. The first sentence fronts the primary return value; the second covers input formats and an important edge case. Every clause earns its place, and there is no redundant filler.

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, the description is complete: it specifies the resource, the response contents, accepted input formats, the null behavior for missing entities, and directs email lookups elsewhere. No output schema exists, but the description adequately covers the return shape. Annotations cover safety and idempotence. Nothing critical 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%, so the baseline is 3. The description essentially repeats the schema's id format ('numeric id or gid://shopify/Customer/<id>') without adding new parameter-level meaning. The email routing comment is usage guidance rather than parameter semantics, so no credit above baseline is warranted.

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 a specific verb and resource: returns a single customer with a defined set of fields (contacts, addresses, note, tags, last 10 orders). It distinguishes itself from list_customers by explicitly noting that email-based lookup belongs to that sibling. The purpose is immediately recognizable 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 provides explicit usage guidance: use this tool for fetching by numeric id or gid, and route email lookups to list_customers with a specific query format. This gives the agent clear conditions for selecting the correct tool among siblings and excludes a common misinvocation pattern.

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