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. It discloses key behavioral traits: the tool performs a conversion (not a read/write operation), outputs in UTC timezone, and returns a formatted string. However, it doesn't mention error handling for invalid timestamps or format strings, or performance characteristics.

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 appropriately sized and front-loaded with the core purpose in the first sentence. The Args and Returns sections are structured efficiently with no redundant information, making every sentence earn its place.

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 (simple conversion), no annotations, and the presence of an output schema (implied by 'Returns' statement), the description is complete enough. It covers purpose, parameters, and return values adequately for this type of utility tool.

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 description adds significant meaning beyond the input schema, which has 0% description coverage. It explains that 'timestamp' represents 'Unix timestamp (seconds since epoch)' and 'format' is a 'strftime format string', including the default format in the schema. This fully compensates for the schema's lack of descriptions.

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 ('Convert') and resource ('Unix timestamp'), and distinguishes it from siblings like 'get_timestamp' (which likely retrieves current time) and 'get_current_time' by focusing on conversion rather than retrieval.

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 context through parameter descriptions (e.g., 'Unix timestamp (seconds since epoch)'), but does not explicitly state when to use this tool versus alternatives like 'get_current_time' or 'time_difference'. However, the purpose is clear enough to infer appropriate usage scenarios.

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