Batch Get Messages

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

Annotations already declare readOnly, idempotent, non-destructive, openWorld behavior, so safety is covered. The description adds only the efficiency rationale and nothing about batch edge cases (partial failures, unknown IDs, the 100-item cap) or what body/config combinations produce.

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?

Two short sentences with no waste; the trigger condition is front-loaded ahead of the rationale, so an agent can decide quickly.

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?

An output schema exists so return values need not be explained, but for an 11-parameter batch tool the description says nothing about the 100-ID limit, behavior when some IDs are invalid, or the relationship to sibling single-message and delete/update batch tools.

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 100% and every one of the 11 parameters, including the four enums, is documented in the schema. The description adds no extra meaning — no guidance on how body_mode and part interact, or when mailbox_id is required.

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 frames the tool as fetching multiple messages in one call and contrasts it with 'repeated single-message calls', which makes the batch-retrieval purpose legible. It never states explicitly that it returns message content by ID, but the name and the ID-based trigger condition make it clear enough.

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 two concrete trigger conditions — the user supplies several message IDs, or a prior search returns multiple candidates — and implicitly names the alternative (single-message calls). It does not state a when-not case, such as fetching one message for full thread context.

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