batch_move_messages

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

With no annotations present, the description carries the full burden, and it delivers: it discloses the pass-through behavior ('Graph resolves well-known names server-side, so we pass through without local resolution'), flags a spec deviation from Spec §6.3, cites the reference implementation, and even records the contingency for a future failure mode. This is unusually rich behavioral context for an agent.

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 front-loaded: purpose first, then destination semantics, with the spec-deviation context placed at the end. The deviation paragraph is somewhat verbose for an AI agent (the file path and contingency plan are developer-oriented), but every sentence about behavior earns its place.

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?

Against a backdrop of no annotations and no output schema, the description covers purpose, destination semantics, pass-through behavior, and its relation to move_message. It does not, however, explain return behavior or partial-failure semantics for a $batch operation, which an agent would want to know for a list-based mutation.

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 compensate. It thoroughly specifies the destination parameter — folder id OR the enumerated well-known names 'archive', 'inbox', 'junkemail', 'deleteditems', 'sentitems', 'drafts' — which is exactly the ambiguity the schema leaves open (no enums, no descriptions). The mailbox parameter, however, gets no semantic explanation beyond its string|null type and default.

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 opening sentence 'Move a list of messages to the given folder' states a specific verb (move), resource (a list of messages), and target (folder). This cleanly distinguishes the tool from its single-message sibling move_message and from batch_archive_messages, which targets only the archive folder.

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 ties the tool's destination semantics to the existing move_message ('the well-known names that move_message already supports'), signaling behavioral consistency with that sibling. However, it never explicitly states when to choose this batch tool over move_message or batch_archive_messages — the selection criteria are only implied by the name and the phrase 'a list of messages.'

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