set_language

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

Annotations declare readOnlyHint=true, which conventionally means the tool does not modify state, yet the description explicitly says it switches output language and that tool descriptions and bridge messages change immediately. This is a direct contradiction between the annotation and the described behavior. The description itself is transparent about the effect, but the contradictory annotation undermines trust and correct agent behavior.

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 compact, bilingual, and front-loaded with the action and allowed values. The English section duplicates the Chinese content, but this duplication is justified for a multilingual tool. It avoids filler and stays focused on behavior and usage.

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 single-parameter tool with no output schema, the description adequately explains what the tool does, what values are allowed, and why auto is useful. It also states the immediate effects on tool descriptions and bridge messages. It does not mention persistence across sessions, but that is not essential given the tool's simplicity.

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%: the input schema already explains zh, en, and auto in both languages, including the 'follow 3ds Max UI language' behavior. The description adds only the extra rationale for auto and repeats the values, so it does not add substantial meaning beyond the schema. Baseline 3 is appropriate.

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 opens with a specific verb and resource: '切换输出语言' / 'Switch the output language', and it enumerates the three accepted values (zh, en, auto) with their meanings. It is clear that this tool sets the language for the MCP service. It does not explicitly differentiate itself from the sibling get_language, though the set/verb distinction is implicit.

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 explains when to choose auto: '用 auto 可以让中英文用户各自看到自己语言的消息，无需手动设置' / 'Use auto so Chinese and English users each get their own language without configuration.' This gives clear context for parameter choice. It does not mention get_language as the read counterpart, but user guidance for this tool is still clear.

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