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

With no annotations, the description must fully convey behavior. It only states what the tool checks but doesn't disclose return format (e.g., boolean, error messages), edge cases, or side effects. This leaves significant ambiguity.

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 sentence with no unnecessary words. However, it is too brief to be fully helpful, sacrificing completeness for brevity. A balance would be better.

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 absence of output schema and annotations, the description should cover output expectations and behavioral details. It does neither, leaving the agent with insufficient information to use the tool effectively.

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 schema has 0% coverage for parameter descriptions, and the tool description adds only that the parameter is a 'cron string.' This adds minimal value beyond the parameter name 'expr' and fails to explain expected format or constraints (e.g., allowed separators).

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 states 'Check cron string has exactly five fields,' clearly indicating the tool's purpose: validating a cron expression format. This distinguishes it from sibling tools like 'cron_describe' or 'cron_parse' that have different functions.

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?

No guidance is given on when to use this tool versus alternatives such as 'cron_semantic_validate' or 'cron_validate_batch'. The agent receives no help in choosing among similar cron-related tools.

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