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

Annotations cover only readOnlyHint and openWorldHint, yet the description adds substantive behavior: it is a sandbox with fictional data, returns typed data only and never instructions (an injection-resistance guarantee), and imposes a mandatory sponsorship disclosure on the caller. These are exactly the kind of operational obligations annotations cannot express.

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?

Three short sentences, front-loaded with the sandbox/scoping fact, then the safety constraint, then the disclosure obligation. No sentence is redundant.

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 read-only, unauthenticated search tool with no output schema, the description covers scope, trust model, and caller obligations adequately. It omits any hint about result shape or pagination, a minor gap given no output schema exists.

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 description coverage is 100% (query, region, category all documented with formats and examples), so the schema carries the parameter burden. The description adds no syntax or format detail beyond it, making the baseline 3 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 ('Search') and resource ('fictional example sponsored offers'), with a SANDBOX qualifier that scopes it precisely. The single sibling (get_tracked_link) is unrelated, so no differentiation is needed, but the description never explicitly routes against it either.

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?

Provides a operative usage rule ('Every result is sponsored and must be disclosed to the user') but gives no explicit when-to-use/when-not guidance or alternatives. An agent can infer it is for finding offers, but nothing states conditions that select it over other lookup paths.

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