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

Discloses key behavioral traits beyond annotations: creating always flips on online participation (created=true → onlineEnabledNowOn=true), existing sessions cause no changes, liveId=null is not a failure and must not be retried, and only self-run/organization activities can create sessions. This is exactly the kind of side-effect and edge-case context that annotations do not carry.

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 description is dense but efficiently structured with labeled sections (when to use, chain, pitfalls), and all sentences carry actionable information. Front-loading the login requirement and use case helps an agent quickly decide whether to invoke it.

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?

Despite no output schema, the description explains return semantics (created flag, liveId null), side effects on onlineEnabled, prerequisites (login, activity type constraints), and relevant link behavior. An agent has enough context to call correctly and avoid retry mistakes.

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 description coverage is 100% for activityRef, so baseline 3 applies. The description does not add parameter-format detail beyond the schema, but it does not need to because the schema already explains slug or id and references get_activity/get_signup_activity.

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?

Description states a specific action: create an activity live session idempotently, returning existing session when one already exists. This distinguishes it from siblings like start_live_session, which actually starts a broadcast, and get_organizer_live, which only reads state. Title also reinforces the organizer and idempotency.

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?

Explicitly states when to use it ('主办方说这场我要开直播'), and gives a combination chain routing to get_organizer_live, the /pro page for stream credentials, and start_live_session as fallback. It also directs when the session already exists and when update_organizer_ticketing should be used instead, providing clear exclusions.

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