Set or clear flag expiry

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

With only idempotentHint and destructiveHint in the annotations, the description carries the substantive behavioral load and does so well: expiry is advisory only, passing dates are refused with EXPIRY_IN_PAST, disabled orgs get FEATURE_NOT_ENABLED, today is allowed, and clearing is always permitted. That is exactly the failure-mode detail an agent needs before calling.

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?

The primary action and the null escape hatch are front-loaded in the first sentence, and every following sentence adds new information. It reads as one dense block rather than segmented guidance, but there is essentially no filler.

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?

No output schema exists, but the description covers the input formats, the advisory nature of the stored value, downstream visibility via find_stale_flags, and both rejection conditions. An agent has everything required to call this correctly and interpret refusals.

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 67% and the description more than compensates: expiresAtUtc accepts either a bare date (interpreted as end of that UTC day, matching the dashboard) or a full ISO-8601 timestamp stored exactly, and null clears. This adds semantics the schema's one-line property description does not convey, including the timezone normalization.

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: setting the date a flag is expected to be removed, with the null case for clearing. It distinguishes itself from sibling mutators like delete_flag and archive_flag by framing the action as scheduling rather than removing, and it names find_stale_flags as the consumer of this state.

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?

It gives clear context for when the tool is appropriate (advisory expiry, cleared via null) and what it is not (evaluation never changes). It does not explicitly contrast with delete_flag/archive_flag, which is the most likely confusion given the sibling set, so it falls short of full alternative-routing guidance.

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