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

Beyond the idempotentHint annotation, the description discloses the two distinct outcomes (created=true vs created=false), the side effect that a new session also flips onlineEnabled on, and that an existing closed session is left untouched. It also documents the liveId=null failure mode and its non-retryable nature, which an agent could not infer elsewhere.

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?

Little is wasted and the key facts come early, but the content is compressed into one semicolon-and-slash chain that mixes auth, idempotency, side effects, error handling, and URL trivia at the same level. Some content, such as the /live/{slug} remark, is tangential and makes the description harder to scan.

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?

There is no output schema, and the description fills that gap fully: it explains created true/false, what onlineEnabled does, and what liveId=null means, so the agent knows what a correct call returns. For a single-parameter, non-destructive tool, nothing an agent needs is missing.

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?

There is a single parameter, and schema description coverage is 100%, so the schema already explains that activityRef takes a slug or id. The description adds nothing further about the parameter; it focuses entirely on outcomes and sibling routing. A 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 tool's job is legible: create the live session for this activity, and it is idempotent ('幂等返回已有场次，不建第二场'). It also separates itself from get_organizer_live and update_organizer_ticketing. The only weakness is that the purpose statement is buried in semicolon-chained clauses rather than stated once cleanly up front.

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 states prerequisites ('先确认开直播'), names the alternative for the reopen case ('重开用update_organizer_ticketing'), routes status checks to get_organizer_live, offers start_live_session as a fallback, and warns not to retry when liveId=null. These are explicit when-to-use and when-not-to-use rules with named alternatives.

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