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

The description discloses the key side-effect: locking availability picking and voting, and that the page shows 已定. It also mentions reopening with start=null and the adminKey requirement, adding meaningful behavioral context beyond the idempotent/read-only annotations.

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 with no filler. The most important constraint ('Organiser only') is front-loaded, followed by the primary action, side-effect, and the reopening behavior.

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?

The description covers the operation's purpose, side-effects, reversibility, and authentication requirement. With a well-described schema and annotations indicating idempotency, nothing essential is missing for an agent to call this tool correctly.

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%, so the schema already fully documents slug, start, and adminKey. The description adds 'start=null to reopen' and 'adminKey from create_event', but these details also appear in the schema descriptions, so little new semantic value is added.

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 states a specific verb and resource: 'settle on a start time' and clarifies the effect 'locks availability picking and voting'. The 'Organiser only' qualifier and the lock-vs-vote distinction differentiate it from vote_time and submit_availability even without naming them.

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 explicitly limits usage to organisers and requires adminKey from create_event, and explains the re-open behavior via start=null. It doesn't explicitly name alternatives or when not to use it, but the context is clear enough to guide selection.

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