MCP Server Framework

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states the tool returns the current Unix timestamp in seconds since epoch, which is useful context beyond the input schema. However, it does not mention potential rate limits, error conditions, or system dependencies, leaving some behavioral aspects unspecified.

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 front-loaded with the core purpose in the first sentence, followed by a clear 'Returns' section. Every sentence earns its place by adding value, with no redundant or verbose language. The structure is efficient and easy to parse.

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 simplicity (0 parameters, no annotations, but has an output schema), the description is complete enough. It explains what the tool does and what it returns, and since an output schema exists, it does not need to detail return values further. The description adequately covers the tool's context without over-explaining.

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 0 parameters, and the input schema has 100% description coverage (though empty). The description does not need to compensate for any parameter gaps, and it appropriately focuses on the tool's function rather than inputs. A baseline of 4 is applied since no parameters are present.

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 specific verb ('Get') and resource ('current Unix timestamp'), distinguishing it from siblings like 'get_current_time' (which might return a formatted time) and 'parse_timestamp' (which converts timestamps). The purpose is unambiguous and directly actionable.

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 implies usage for obtaining the current Unix timestamp, but does not explicitly state when to use this tool versus alternatives like 'get_current_time' or 'parse_timestamp'. No guidance is provided on exclusions or prerequisites, leaving usage context to inference.

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