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

Annotations already cover readOnly/idempotent/non-destructive, so the description doesn't need to re-litigate safety, yet it adds genuinely useful semantics: "Planned dates are not confirmed ship dates" and "Read coverage distinguishes unknown from absent." That unknown-vs-absent distinction is important behavioral context an agent cannot get from the schema or annotations. It does not describe response shape, pagination, or failure modes, so it stops short of a 5.

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?

Purpose leads, followed by two short caveat sentences that each earn their place. The one weakness is that the first sentence is a long run-on field enumeration that largely restates the tool title, adding length without adding routing value, though the field list does aid discovery.

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 return content and does so thoroughly by enumerating the account facts returned, plus caveats on date certainty and coverage semantics. It omits prerequisites (what happens if the case has no linked customer, or if the customer has no subscriptions) and any auth/scoping notes, so it is strong but not fully 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?

Schema coverage is 67%: company and environment carry descriptions, while the required case UUID has none. The description says nothing about any of the three parameters, not even that case identifies which customer's account is read, so it neither compensates for the uncovered case parameter nor adds meaning beyond the schema. A 3 is the appropriate baseline at this coverage level.

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 definition names a concrete verb ("Read") and concrete resources ("the case customer's subscriptions and upcoming shipments"), and it enumerates the exact facts returned: renewal/next-charge dates, price/currency, pauses, refill due dates, fulfillment, tracking. That grounds it against vaguer siblings such as summer_cases_get or summer_client_status, though it never explicitly names a sibling or states what it is not.

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 is only implied: it targets a case customer's account facts and is framed as the same data used by the chat agent and Details panel, so an agent can infer it should be called when a case context exists. There is no explicit when-to-use, when-not-to-use, and no alternative named (e.g., summer_cases_customer_profile or summer_cases_get) among the many case siblings.

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