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

Annotations already declare readOnlyHint=true, openWorldHint=false, destructiveHint=false, so safety is covered. The description adds real context beyond them: results include prices, a shop_url is provided, and purchasing must happen on that page, not in chat — an important constraint on downstream behavior. It doesn't cover empty results or pagination, keeping it from 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?

Two tight sentences with zero filler; the resource scope comes first and the purchase-routing constraint second, which is the right order for an agent reading top-down.

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 does the necessary work of naming what comes back — packages, memberships, gift-card availability, prices — and how to act on shop_url. It falls slightly short on edge cases (no offers, multiple locations) but is otherwise sufficient for a simple read.

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 100%, with both business and location_id fully documented in the schema, so the baseline 3 applies. The description says nothing about location scoping or the default-to-first-location behavior that the schema documents.

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?

It states the resource precisely: session packages, memberships and gift-card availability, plus prices. It's clear and specific, but there's no sibling differentiation — an agent can't tell from the description alone how this differs from list_services (services vs. packages), which is the closest neighbor.

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 implied by the resource name; the description does not say when to call this versus list_services or get_business. The one explicit instruction — "give the person shop_url to buy" — is post-retrieval routing guidance rather than tool-selection guidance.

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