Utility MCP Server

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

With no annotations provided, the description carries full burden and does well: it discloses the default timezone behavior, mentions worldwide timezone support, describes the return format, and specifies error conditions (ValueError for invalid timezone). It doesn't mention rate limits or authentication needs, but those are less critical for a time lookup tool.

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 well-structured with clear sections (purpose, usage, Args, Returns, Raises), front-loads the core functionality, and every sentence adds value. No wasted words while maintaining completeness.

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 tool's low complexity (single optional parameter), no annotations, but having an output schema, the description is complete: it explains purpose, usage, parameter semantics, return format, and error conditions. The output schema existence means the description doesn't need to detail return structure, and it appropriately focuses on semantic context.

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 input schema has 0% description coverage and only shows a string parameter named 'timezone'. The description compensates fully by explaining what the parameter means ('时区名称'), providing concrete examples of common timezones with their human-readable names, and mentioning the default value. This adds significant value beyond the bare 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?

The description clearly states the tool's purpose with specific verb ('获取') and resource ('当前时间'), and distinguishes it from siblings by specifying it's for current time (not formatting or getting timestamps). It explicitly mentions '指定时区' (specified timezone), making the scope clear.

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 provides explicit guidance on when to use ('当AI需要知道当前时间时可以调用此工具') and includes a default behavior ('默认使用中国标准时间'). It distinguishes from siblings by focusing on current time rather than timestamp manipulation or formatting.

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