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

The annotations already declare this as a safe, read-only, closed-world operation, so the description's burden is lighter. It adds useful behavioral context by saying the analytics cover the signed-in merchant or a partner's customer set and by listing the kinds of results returned, though it does not describe response shape or limits in more detail.

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 compact sentences, front-loaded with the main purpose, followed by date format and partner-specific parameter behavior. It is dense but wastes no 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 an analytics tool with no output schema, the description gives a useful summary of returned categories and covers partner scoping and date format. It does not fully describe the chart or response structure, but it is complete enough for an agent to select and invoke the tool correctly.

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 adds meaning beyond the schema by explaining partner aggregation behavior: omit organisationId to analyze the whole book, or pass one customer organisation id for that customer.

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 states a specific resource and scope: full shipment analytics for the signed-in merchant or a partner's customers, and it enumerates the included metrics (order/label/return counts, carrier mix, delivery performance). It is clear what the tool does, but it does not explicitly distinguish itself from nearby reporting/partner tools such as PartnerSummary or SummarizeUsageRecords.

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?

Usage context is implied by the merchant-vs-partner framing and by the instruction that partners omit organisationId for the whole book or pass one customer organisation id. However, the description does not explicitly state when to use this tool rather than sibling reporting or investigation tools, and it gives no exclusions.

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