Messages status

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

With no annotations, the description carries the full burden and does real work: it discloses that message bodies are never returned, that it surfaces a likely-missing Full Disk Access condition, and that 'unscoped' is gated on MESSAGES_ALLOW_UNSCOPED=1. It omits cost/latency and read-only confirmation, but for a zero-parameter status probe this is solid coverage.

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?

Front-loaded with the core verb ('Report whether...') and packs many diagnostics into one tight sentence, followed by the usage cue and two exclusion/semantics notes. Every clause carries information, though the MESSAGES_ALLOW_UNSCOPED sentence is a fine-grained detail.

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?

There is no output schema, so the description must describe what comes back — and it enumerates the returned status fields explicitly. For a no-parameter, no-annotation diagnostic tool, nothing an agent needs to call it correctly is missing.

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 takes no parameters, so there is no parameter semantics to document. Baseline 4 applies for a zero-parameter definition.

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?

States a specific verb ('Report') and enumerates the exact diagnostics it returns: db readability, Full Disk Access status, macOS hints, send/redact flags, snapshot size/age, and inbox scoping. This is clearly distinct from the sibling list/search/thread tools, which handle message content rather than health status.

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?

'Call this first when anything fails' gives an explicit, actionable trigger condition. It doesn't name specific alternatives or state when-not-to-use, but the diagnostic nature makes the boundary with the content-reading siblings self-evident.

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