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

Without annotations, the description carries full behavioral burden. It discloses that the catalog is 'live' and prices are in ZAR, implying a read-only, real-time operation. However, it omits pagination behavior, response completeness, authentication needs, or any rate-limit considerations.

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?

A single front-loaded sentence that efficiently conveys the resource, included items, and pricing currency. Every element earns its place without redundancy.

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?

For a simple list tool with one optional parameter and no output schema, the description adequately explains what is returned (catalog with item types and pricing). Minor gaps remain regarding response format and pagination, but the core information an agent needs is present.

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% and the sole optional 'category' parameter is fully described with examples in the schema. The description does not mention the parameter or add any filtering semantics beyond what the schema already provides, so baseline 3 is appropriate.

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?

States a specific verb ('Fetch') and resource ('live Agua é Vida product catalog'), and enumerates the included product types and pricing currency. It is clearly distinguishable from all siblings, which handle delivery, checkout, rentals, store info, and order tracking rather than catalog listing.

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 description gives no indication of when to use this tool versus alternatives, no preconditions, and no exclusions. It only says what it fetches, leaving the agent to infer that this is the tool for product browsing.

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