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

With no annotations provided, the description fully discloses the tool's behavior: it echoes client_msg and appends server_msg. It also explicitly lists the return fields (client_msg, server_msg), providing transparency beyond the schema alone. It does not explicitly state there are no side effects, but the utility nature is implied.

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 well-structured sentences. It front-loads the tool type [utility] and health check purpose, then details the behavior and return fields. Every sentence earns its place with zero waste.

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 simple echo utility with one parameter and no output schema, the description is complete. It explains the purpose, the exact behavior, the parameter's role, and both return fields. An agent can confidently invoke this tool correctly based on the provided information.

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%: client_msg is already described as '任意字符串，服务端原样回显（原始字符串，非编码格式）'. The tool description reiterates this same meaning without adding new parameter-level details, so it provides no additional value beyond the schema.

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 clearly states it is a health check / echo interface, with a specific verb ('回显' - echo back) and resource (client_msg). It explicitly distinguishes itself from sibling crypto tools by describing its utility purpose (verifying MCP channel connectivity).

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 intended use case: '用于验证 MCP 通道连通性' (to verify MCP channel connectivity). It provides clear context for when to use the tool, though it doesn't describe exclusions or alternatives, which is acceptable given the sibling tools are unrelated crypto functions.

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