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

Annotations already cover safety (readOnlyHint, idempotentHint, non-destructive), so the description's job is to add operational detail, and it does: explicit ordering (most recent first), unit of return (one row per order), the implied 50-row ceiling, and the fact that calls consume no credits. It omits whether results paginate or how to reach orders beyond the cap.

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 core content is two tight, front-loaded sentences that lead with the returned data shape and then route to the alternative. The appended MCP transport and free-credit sentences are boilerplate but short and do not bury the main point.

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?

With no output schema, the description carries the burden of describing returns, and it does list the key columns, which is helpful. But it leaves out pagination behavior for the 50-row maximum and the exact effect of a status filter on result ordering — gaps an agent would hit on the first call against a large date range.

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 75%, so the schema largely documents from/to, limit and accountIds itself. The description only adds the practical implication of the 50 cap ('instead of fifty') and the status filter by mentioning financial status; accountIds, userStatement and idempotencyKey receive no coverage in prose.

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 granularity: order-level rows, most recent first, with totals, financial status, fulfilment status and line count. It distinguishes itself from store_revenue by contrasting per-order listing with period aggregation. The verb phrase 'Orders one by one' is slightly awkward but the intent is 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?

It names a concrete alternative and the condition selecting it ('For a total over a period, store_revenue costs one call instead of fifty'), which is exactly the routing an agent needs. However, 'For looking at a specific order' is misleading because no order identifier parameter exists, and it does not mention when to prefer store_customers or store_products.

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