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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful non-annotation detail, the Happy Hamper login requirement, but says nothing about failure modes such as an out-of-service-zone address or missing options.

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?

Two sentences, no filler; the returned-field enumeration is front-loaded and the auth prerequisite is a short trailing clause. The first sentence is dense with field names but every item earns its place by pre-describing an output that has no output schema.

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 usefully enumerates the return shape (serviceZoneScheduleId, day, frequency, nextDate, backDate, prices with discount), and the auth prerequisite is covered. Remaining gaps are error and empty-result behavior for a single-required-param read tool, which is a minor omission.

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 single addressId parameter has 0% schema description coverage, so the description must carry the load. 'At one of their addresses' implies the id must be a customer-owned address, which is real added meaning, but format and source (e.g. from get_account) are never specified.

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 names a specific resource and scope: the subscription options a customer can start at one of their addresses, plus the exact fields returned. It is clearly not a booking or quote tool, but it never names a sibling (quote_one_time_pickup, get_service_info, start_subscription) to sharpen the boundary.

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: because the tool returns 'subscriptions the customer can start', an agent can infer it is the discovery step before start_subscription, and the login prerequisite is stated. There is no explicit when-to-use, when-not-to-use, or stated alternative.

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