从微信窗口列出最近聊天

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

Beyond annotations (readOnlyHint, destructiveHint, idempotentHint), the description discloses the OCR mechanism, UI-level reading, and guarantees no data modification beyond interface content. Full consistency with 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?

The description is extremely concise: two sentences front-loading the condition and method, with zero redundancy. Every sentence provides essential information.

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?

Given the existence of an output schema, return values are not needed. The description covers the tool's behavior well but lacks parameter documentation. Considering tool complexity (OCR, UI interaction), it is mostly complete.

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%, yet the description provides no information about the 'limit' or 'response_format' parameters. The schema defines defaults and types, but the tool description adds no semantic value for parameters, leaving the agent to infer from names alone.

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 clearly states the tool uses OCR to read recent chats from the current WeChat window when the database snapshot is not ready. It distinguishes itself from database-based siblings like wechat_list_chats and wechat_recent_messages by specifying the UI-based approach.

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?

The description explicitly states the condition for use ('when the plaintext database snapshot is not yet ready'), implying that alternatives should be used otherwise. It does not name specific sibling tools but provides clear context for when this tool is appropriate.

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