delete_messages

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

With no annotations provided, the description carries the full burden and does well: it discloses that the operation is recoverable from Deleted Items, that copies are created (hence new_message_ids), and that a confirmation-count guard exists. It stops short of describing failure behavior for invalid or partial id sets, which is the remaining gap.

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 action and the key sibling distinction, then the parameter rule, then the return value. Every clause adds information; the indented confirm_count block reads as a deliberate callout rather than filler.

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?

For a two-parameter mutation tool with no annotations or output schema, the definition covers recoverability, the confirmation protocol, and what is returned. What is missing is id provenance/format and error behavior when ids are unknown or the count mismatches.

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 coverage is 0%, so the description must compensate. It explains confirm_count thoroughly (must equal the number of ids, omitted on the first call) but leaves message_ids undocumented — no statement of expected id format or where to obtain ids, despite siblings like search_message_ids existing. Half the parameters are covered well, half not at all, so the midpoint is fair.

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 and resource ('Move messages by id to Deleted Items') and immediately distinguishes itself from the sibling permanently_delete_messages. An agent can pick between the two deletes without opening either 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?

Explicitly frames this as the default delete and reserves the sibling for an explicit purge, giving a clear when-to-use rule. It also specifies a two-step invocation protocol (call without confirm_count first, show the user the list), which is real operational guidance rather than restated field names.

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