unix_timestamp

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

With no annotations provided, the description carries the full burden. It does explain the bidirectional conversion behavior, which is good. But it omits details about the 'now' special value (mentioned in the schema) and does not discuss edge cases like error handling or ambiguous inputs. For such a simple tool, this is adequate but not comprehensive.

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 a single, front-loaded sentence that states the tool's purpose and usage without wasted words. Every clause earns its place, making it highly concise and well-structured.

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 (one parameter, no output schema, no nested objects), the description covers the essential behavior well. It explains the two conversion directions and implicitly covers the accepted input types. It could have mentioned the 'now' special value from the schema, but the schema itself handles that, so the description's coverage is sufficient for an agent to use the tool correctly.

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 coverage is 100% for the single parameter 'value', so the baseline is 3. The description adds value by explaining the input-output relationship ('Pass a timestamp to get ISO, or a date to get timestamp'), which goes beyond the schema's type enumeration. It clarifies that the direction of conversion depends on the input format, which the schema does not explicitly convey.

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 'Convert between Unix timestamps and ISO 8601 dates', which is a specific verb+resource pair. It clearly distinguishes this from sibling tools like 'convert_timezone' (timezone conversion) and 'format_date' (date formatting), making the purpose unambiguous.

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 clear usage direction: 'Pass a timestamp to get ISO, or a date to get timestamp.' This tells the agent exactly what input leads to what output. However, it does not explicitly mention when not to use this tool versus alternatives like 'convert_timezone' or 'date_math', so it lacks exclusion guidance.

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