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

With no annotations provided, the description carries the full burden of disclosing behavioral details. It does disclose an important nuance: 'Uses standard Unix OR semantics for day fields.' This is non-obvious and valuable. However, it does not mention other behavioral aspects such as timezone handling, exact output format, or behavior for invalid expressions. The description provides a key detail but is not exhaustive.

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 consists of two sentences. The first sentence is action-oriented and front-loaded with the core purpose. The second sentence adds a crucial behavioral nuance without unnecessary filler. Every word earns its place; it is 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 simplicity (3 parameters, no output schema, no annotations), the description is moderately complete. It explains the core function and a key semantic, but it does not specify the output format (e.g., list of ISO timestamps) or error behavior. Since there is no output schema, the agent must infer the return structure from the description, which leaves room for ambiguity. The description is adequate but could be more thorough.

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 description coverage is 100%, and each parameter (expression, from, count) already has a description in the schema. The tool description adds no new parameter-specific meaning beyond implying 'N' corresponds to 'count'. It does not refine the definition of 'expression' or 'from'. The baseline score of 3 is appropriate because the schema does the heavy lifting, and the description adds minimal parametric insight.

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: 'Get the next N scheduled run times for a cron expression.' This identifies a specific verb ('Get'), a resource ('run times'), and the input ('cron expression'). It distinguishes itself from siblings (common_crons, diff_cron, explain_cron, generate_cron, validate_cron) by focusing on computing future occurrences rather than generating, validating, or explaining cron expressions. The added note about Unix OR semantics further clarifies its behavior.

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 when to use the tool: whenever an agent needs to determine future run times for a cron expression. However, it does not explicitly mention alternatives or provide 'when not to use' guidance. Given the existence of sibling tools like validate_cron and generate_cron, explicit differentiation would improve the score. The use case is clear but not contrasted with alternatives.

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