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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful non-obvious behavior: unrevealed codes are masked to label plus last characters, while revealed ones return the full code — this tells the agent what it will and won't get back.

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 tightly written sentences, zero filler, with the resource identity front-loaded and the masking behavior immediately after. Nothing to cut.

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 carries the return-value burden and does so for the key distinction (masked vs. full code). Minor gaps remain: no mention of pagination/ordering or how to obtain the revealed state, which is exactly what reveal_codes exists for.

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?

Only one optional parameter (api_key) and it is fully documented in the schema, including when it is unnecessary. The description adds nothing about it, but with 100% schema coverage the baseline of 3 applies.

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 the resource precisely — gift card/voucher codes that arrived by mail — and explains the two content states (waiting vs. revealed). It does not, however, distinguish itself from the sibling reveal_codes, which is the most likely confusion point.

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?

There is no explicit when-to-use statement and no mention of when to call reveal_codes instead. An agent must infer that this tool lists and the sibling reveals, which is left entirely implicit.

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