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

The description adds meaningful behavioral nuance beyond the annotations: it explains the opener=null case and that the effective message is the platform default, preventing the agent from misinterpreting null as an error. This is exactly the kind of context annotations cannot convey.

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 organized into clear labeled sections: when to use, combination chain, and pitfalls. Every sentence adds value, and the critical null/effective caveat is given dedicated space. It is concise despite covering several important aspects.

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 zero-parameter read-only tool with no output schema, the description covers what the agent needs: when to call it, how it fits with sibling tools, and the key semantic trap (null vs effective). Nothing important 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?

The tool has zero parameters, so the schema covers everything trivially. The description adds no parameter detail, but none is needed. Baseline 4 for no-parameter tools applies.

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 identifies the tool as a read operation for the user's chat opener, with explicit use cases: '要改开场语之前先读现状' and answering what others see when contacting. It also implicitly differentiates from the sibling set_my_chat_opener by naming it in the combination chain.

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?

Provides explicit when-to-use guidance: read before editing, and when users ask what others receive. It also gives a usage chain, telling the agent to use set_my_chat_opener after reading, and to read get_my_card/get_my_products before writing. This is clear and actionable.

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