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

With no annotations, the description carries the full burden and does: it enumerates what transfers (messages, files, notes, drafts), states the old number continues to route to the surviving case, that the merged ticket is gone, that an audit note is written with the supplied reason, that a pending draft is set aside, and that the action is irreversible. That is unusually complete disclosure for a destructive mutation.

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 purpose and effect, then constraints, with zero filler sentences. It is dense and slightly long, but every clause conveys a distinct fact an agent needs before an irreversible merge.

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?

No annotations and no output schema, so the description must supply safety, side effects, and preconditions — and it does all three, including irreversibility, the note side effect, and the queue/contact requirement. Nothing material to calling this correctly is missing.

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 100%, so baseline is 3; the description adds the disambiguating meaning of 'into' ('the ticket that stays') and a behavioral directive for 'note' — it is embedded in the merge note, so don't add a second one via add_note. That is genuine value beyond the schema, though it does not extend the identifier syntax beyond what the schema already documents.

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 ('Merges a helpdesk ticket into another') plus the binding constraint (same contact), and the scenario sentence ('client who wrote again beside their case rather than in it') pins down the distinct intent. An agent can distinguish this from delete_conversation, file_conversation, or assign_conversation without opening a 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?

Gives a clear triggering scenario and hard preconditions: 'Both must be tickets of a support queue you can open, with the same contact; a mailbox thread is refused.' It never names a sibling alternative (e.g. file_conversation or delete_conversation) for the cases it excludes, so routing for the refused mailbox case is left implicit.

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