list-smart-mailboxes

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

With no annotations, the description carries the behavioral transparency burden. It discloses a notable edge case (German-localized macOS where AppleScript terms don't compile) and mentions the return content ('name and a short criteria summary'). While it doesn't explicitly state non-destructive intent, 'listing' implies read-only, and the edge case adds valuable behavioral 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 extremely concise, with two clear sections ('Use when' and 'Returns') and a 'Do not use when' clause. Every sentence serves a purpose, and the most critical usage direction is front-loaded.

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 zero-parameter list tool with an output schema, the description covers purpose, usage boundary, an important localization nuance, and return value summary. It is fully sufficient for an agent to select and invoke 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?

The tool has zero parameters, so the baseline for this dimension is 4 as per the rubric. The description doesn't need to add parameter semantics, and it correctly stays silent on parameters. The mention of 'criteria summary' is about the return value, not an input.

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 specifies the exact action ('listing Apple Mail smart mailboxes') and clearly distinguishes it from the sibling tool by stating 'Do not use when: listing real folders/mailboxes (use list-mailboxes)'. This makes the purpose unambiguous and differentiates it from closely related tools.

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 explicit 'Use when' and 'Do not use when' instructions, naming the alternative tool (list-mailboxes). This meets the highest standard for usage guidance.

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