run_background_sync

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

No annotations are provided, so the description bears full responsibility. It discloses the action (trigger sync), dependency (AUTO_SYNC), and return value (updated status). However, it doesn't mention whether the operation is synchronous or asynchronous, or if there are rate limits or side effects, leaving some 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 two sentences, front-loading the action and purpose, followed by usage guidance. Every sentence adds value, and there is no redundancy or wasted words.

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?

Without an output schema, the description mentions 'return its updated status' but doesn't specify what the status includes (e.g., sync completion, errors, next schedule). It also doesn't clarify if the tool blocks until sync finishes. For a zero-param tool, these details would enhance completeness.

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 schema coverage is trivially 100%. The description adds no parameter details, but none are needed. Baseline for 0 params is 4, and the description adequately explains the tool's action without parameter references.

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 uses a specific verb ('trigger') and resource ('background mailbox sync cycle'), and clarifies it runs outside the normal schedule. It also states the output (updated status) and gives a use case ('when the index may be stale'), clearly distinguishing it from sibling tools like sync_emails.

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 states when to use ('force a sync when index may be stale'), when not to use ('does nothing useful if PROTONMAIL_AUTO_SYNC is disabled'), and recommends an alternative (sync_emails) with reasons (on-demand, configurable). This provides excellent decision support.

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