create-newsletter-smart-mailboxes

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

With no annotations provided, the description fully bears the behavioral disclosure burden. It reveals the default dry-run safety, the fact that dryRun=false edits Apple Mail's SyncedSmartMailboxes.plist with backup and atomicity, that existing entries are preserved, and that the scan can be slow on large mailboxes. This is exceptionally transparent for a mutation-capable tool.

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 well-structured with labeled sections (Use when, Returns, Do not use when, Safety), and every sentence provides valuable information. It is appropriately sized for a complex tool and front-loads the primary use case.

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?

The description covers purpose, usage alternatives, return values, safety, side effects, and performance. Given the tool's complexity (3 parameters, no annotations, output schema present), the description is complete and self-sufficient. Output schema exists so return format details are not required in the description.

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 coverage is 100%, so the baseline is 3. The description adds some behavioral context for dryRun (safe proposal vs. actual creation) but does not significantly expand parameter semantics beyond what the schema already documents. The 'scans up to ~400 recent messages' detail adds performance context rather than clarifying parameter meaning.

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 purpose: auto-discovering newsletter/bulk senders in inboxes and optionally creating a dedicated smart mailbox per sender. It uses specific verbs and names the resource (INBOX(es) and smart mailboxes), and it distinguishes itself from create-smart-mailbox and create-mailbox.

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 explicitly provides 'Use when' and 'Do not use when' sections, naming alternative tools (create-smart-mailbox for known senders, create-mailbox for real folders). This gives clear contextual guidance for when to select this tool vs. siblings.

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