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

Goes beyond the annotations with real behavioral detail: the conversation's lead is reassigned along with it (a side effect an agent must know before mutating), and the assignment is audited as made by the API key's creator. It also enumerates authorization failures (403 agent_not_authorized, 404 agent_not_found/not_found, 422 assignee_not_allowed). It stops short of saying whether the new assignee is notified or whether a previous assignee is cleared.

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 body is dense and front-loads the core semantics (assign vs unassign) before prerequisites and error codes. The opening line duplicates the tool title verbatim, which is a minor waste, but every subsequent sentence carries information an agent needs.

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 four-parameter mutation with no output schema, it covers prerequisites, side effects, audit attribution, and the main error paths, which is close to complete. The remaining gap is the return value or observable result of a successful call, which the description never mentions despite there being no output schema to fall back on.

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 the baseline is 3; the description earns above-baseline credit by tying assigned_to to its valid source (listAgentMembers user_ids with can_open_agent true) and by reassuring that the field is required so an empty body cannot accidentally unassign. The reason parameter is left entirely to the schema.

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 the specific verb and resource ('Assigns the conversation to a teammate') and explicitly covers the inverse operation ('unassigns it with "assigned_to": null'), which no sibling does. The resource is unambiguous against siblings like assign_lead, so an agent can tell which entity is being mutated 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?

Gives a clear precondition for valid use ('The teammate must be able to open the agent: a user_id from listAgentMembers with can_open_agent: true') and maps the failure to a concrete code ('422 assignee_not_allowed'), which is genuinely actionable routing information. It does not, however, name alternatives or state when *not* to use this tool versus assign_lead or update_conversation.

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