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

The annotations already declare readOnlyHint=true, and the description is consistent with that. Beyond the annotations, it adds real behavioral context: access is permission-gated, evidence/CDKey/redemption codes and check-in uploads are only available inside the user's own App, and viewing does not imply registration or a win. It does not describe response shape or pagination behavior, but the read-only profile is well covered.

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 extremely compact and front-loaded with the access prerequisite and permission gate, then parameter semantics, then scope boundaries. Every clause carries distinct information with no repetition of the schema or annotations.

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 tool with three parameters and no output schema, the description covers the prerequisites, the meaning of two parameters, and the important limitation that sensitive artifacts live only in the App. The main remaining gap is the format or semantics of activityRef and any hint about the returned draw records.

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 0%, so the description must carry the parameter meaning, and it does for the two non-obvious ones: 'draws取最近limit条' explains that limit bounds the most recent draws, and 'includeFairness取匿名凭据' explains that includeFairness returns anonymized credentials. Only activityRef is left undiscussed, though its meaning is largely evident from the name.

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 names a specific verb and resource in '按权限读抽奖' (read the raffle per permission), and it clarifies the boundary '查看不代表报名或中奖' (viewing does not mean registering or winning), which separates it from act_activity_raffle. It does not explicitly name that sibling, so the distinction is implied rather than stated.

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 a prerequisite ('登录' – must be logged in) and a permission condition ('按权限读'), which is useful context. However, it never says when to use this tool instead of act_activity_raffle or configure_activity_raffle, so the agent must infer the routing from the names alone.

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