list_rules

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

With no annotations, the description carries the full burden. It discloses a key behavioral trait—that the tool returns ALL rules, including ones created outside this tool—which adds value beyond the name. It also implies read-only behavior via 'List'. While it doesn't discuss edge cases or side effects, it's adequate for a simple list operation.

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 compact—two sentences—and front-loaded with the core purpose. The additional sentence adds meaningful detail (scope and return fields) without waste. Every word earns 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?

For a simple no-parameter list tool, the description is complete. It specifies what will be listed, the fields included, and the comprehensive scope. No output schema exists, but the description sufficiently conveys the expected return content. Sibling tools are numerous, but the description clearly carves out this tool's role.

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?

There are zero parameters, so the baseline is 4. The description adds no parameter-specific details, but none are needed. The schema coverage is trivially 100% with no properties, so no compensation is required.

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 lists all Apple Mail rules with specific fields (name, enabled state, move-target folder, sender domains). It uses a specific verb ('List') and resource ('Apple Mail rules'), and distinguishes from siblings like create_rule/delete_rule by focusing on enumeration.

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 this tool: to see every rule in Mail, including those not created via this tool. It provides clear context but does not explicitly name alternatives or exclusions. However, the phrase 'shows every rule' effectively differentiates it from other rule-related tools.

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