voidmail_send_status

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

Annotations already cover readOnly/idempotent/non-destructive, so the description adds genuinely new behavioral facts: that reading consumes no send quota and that 'Provider acceptance does not mean recipient delivery.' These are non-obvious semantics that change how an agent interprets the result, not restatements of the annotations.

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?

Four compact sentences, front-loaded with the core purpose before the caveats. Each sentence carries distinct meaning, though the last two cautionary sentences are dense and border on instruction-manual phrasing.

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, and the description compensates by flagging the non-authoritative status states (unknown/missing/unavailable) and the acceptance-vs-delivery gap an agent must not over-read. It covers what an agent needs to act correctly, leaving only minor gaps about the enumeration of statuses.

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?

With one parameter at 100% schema description coverage, the schema already documents operationId's format and lifecycle. The description adds no syntax or usage detail for the parameter, so baseline 3 applies for a schema that does the heavy lifting.

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 states a specific verb and resource: 'Read a retained send operation owned by this mailbox.' It is clearly distinct from write siblings like voidmail_send_email, voidmail_send_once and voidmail_revoke_recipient, though it never names a sibling explicitly. An agent can identify the operation without opening the schema.

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 a strong contextual rule: 'Unknown, missing or unavailable status never authorizes a replacement send,' which tells the agent when NOT to act on this result. It stops short of naming alternatives (e.g. re-reading vs re-sending), so it is clear context without explicit routing.

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