UniFi: List Vouchers

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

With readOnlyHint=true already covering the safety profile, the description adds genuine behavioral value: it discloses that expired vouchers are not deleted automatically and will still appear in results, which an agent would not otherwise assume. It also previews the return content, giving the agent expectations for what a successful call yields without an output schema.

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 sentences with zero waste. The first sentence front-loads the purpose and return fields; the second delivers the expiry gotcha and the corrective filter. Both sentences earn their place, and information density is high without becoming a wall of text.

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 list operation with zero required parameters, a complete schema, and a safety annotation, the description covers the essentials: what is returned, the key behavioral caveat (expired vouchers persist), and the filter that addresses it. Minor gaps — no explicit ordering, pagination hint beyond what the limit param already states — are negligible given the schema richness.

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 schema's own parameter descriptions are exceptionally rich (site resolution across three forms, full filter-expression syntax, limit defaults and rejection behavior). The main description adds only the `expired: false` hint, which largely restates the schema's 'false for still-valid ones.' The schema carries the weight here, 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?

The description opens with a specific verb and resource — "List the hotspot guest vouchers on a site" — and enumerates the returned fields (code, name, time/data limits, guest usage count, activation/expiration). This clearly distinguishes it from sibling list tools like unifi_list_clients, unifi_list_devices, and unifi_list_sites, all of which target different resources.

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 conditional filtering guidance ('filter with `expired: false` for the ones still usable') and explains why the filter is needed, which is useful context for when to apply it. However, it never names alternatives or states when NOT to use this tool versus a sibling list tool or unifi_request, leaving tool-selection reasoning mostly to inference.

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