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

Annotations provide readOnlyHint=true, which covers the safety profile. The description adds no behavioral details beyond the core purpose, such as handling of invalid expressions or output format specifics. It does not contradict annotations, but it also offers no extra context.

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 with zero unnecessary words. It immediately communicates function without redundancy.

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 tool with one simple parameter and no output schema, the description fully conveys the input and the nature of the output ('human-readable description'). It is complete for the tool's complexity.

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?

Input schema coverage is 100%, with a clear description 'Five-field cron expression' for the only parameter. The tool description adds no additional parameter semantics beyond restating that it accepts a cron expression. Baseline 3 is appropriate since schema already carries the load.

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 function: 'Convert a cron expression to a human-readable description.' It uses a specific verb ('Convert') and resource ('cron expression'), and the result is clear. It distinguishes from sibling tools like dev_timestamp_convert and dev_regex_test by focusing on cron expressions.

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?

Usage is implied: the tool should be used when one has a cron expression and needs a human-readable explanation. However, there is no explicit statement of when to use it vs. alternatives, nor any exclusions. The description is minimal and relies on the tool's name and obvious purpose.

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