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

The annotations already establish that this is a safe, read-only, idempotent lookup. The description adds meaningful behavioral context beyond that: the query must use exactly one selector mode, time ranges are capped at seven days, and results can include failed, unknown, or blocked outcomes.

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 a single dense but well-structured sentence. The core resource scope is front-loaded, followed by the selector constraints and range limit, with no redundant wording.

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?

With an output schema and annotations already present, the description only needs to supply query semantics and constraints. It covers the critical selector exclusivity and bounded-range rules, though pagination via limit/cursor and the optional status filter are not described.

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 description coverage is 0%, so the description must carry parameter meaning. It does explain request_id, idempotency_key, since, and until, including the exclusivity rule and seven-day maximum, but it leaves limit, cursor, and status filter semantics unexplained.

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 resource and scope: status of MCP-originated outbound requests, including drafts, approvals, scheduled sends, and provider outcomes. It is specific enough to distinguish this from general message or conversation tools, but it does not explicitly contrast itself with any sibling tool.

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?

It gives important usage constraints: exactly one of request_id, idempotency_key, or a bounded time range, and explicitly excludes unbounded enumeration. However, it does not explain when to use this tool versus related siblings such as list_scheduled_messages or list_messages.

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