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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds genuinely useful context beyond them: the return shape is a current price plus either a one-time cart link or a website subscription path, and in-chat checkout availability depends on the shopping platform. The closing 'Read-only' is redundant with readOnlyHint but not contradictory.

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?

Four short sentences, front-loaded with the core matching function and followed by return/output behavior. Every sentence carries information except the trailing 'Read-only,' which duplicates an annotation.

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 correctly carries the return-value burden (price, cart link, subscription path) and notes the platform dependency for in-chat checkout. It does not cover edge cases such as no-match behavior or whether the cart link expires, leaving minor gaps for a two-param tool.

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 enums documented, which sets a baseline of 3. The description earns above baseline by mapping values to behavior: 'first purchase, a group or a refill' echoes the need enum, and 'one-time cart link or the website subscription path' explains the consequence of each purchase value.

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?

Specific verb+resource: it 'matches' a shopper need to a 'live product' and states what comes back (price plus cart link or subscription path). That inherently separates it from catalog siblings like get_products and from cart-mutating siblings like build_cart, though no sibling is named explicitly, so it stops short of a 5.

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?

The opening sentence implies when it applies (a first purchase, a group, or a refill) and the purchase enum hints at routing, but there is no explicit when-to-use versus get_products/build_cart/where_to_buy, and no exclusion conditions. Usage is inferable rather than stated.

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