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

Annotations already declare the mutation is non-destructive and idempotent; the description adds genuinely new behavior — name resolution must match exactly one current teammate or the call is refused, and the same idempotency_key must be reused on retries. It does not describe the response or what happens to a previously assigned teammate, but the refusal semantics and retry contract are the key extras.

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, then parameter semantics, then the refusal rule and retry advice — every clause carries information. The semicolon-heavy first sentence is dense but not padded.

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, the definition covers the two ambiguous parameters, the unassign case, the failure mode, and idempotency, which is what an agent needs to call it correctly. Missing only the return shape and any permission/ownership prerequisites.

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 only 25%, so the description must compensate and largely does: it explains assigned_member_id's provenance (read entity org_members), that null unassigns, and that assigned_to is an exact-name alternative that is rejected on ambiguity. conversation_id is left implicit, which is a minor gap only.

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 ('Assigns a conversation to a teammate') and anchors it to a concrete UI analogue (the thread header's Assign menu), which unambiguously separates it from siblings like assign_task or link_conversation_to_client.

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 clear usage conditions: use assigned_member_id, or pass assigned_to by exact name, or pass null to unassign. It does not explicitly contrast with assign_task or state preconditions such as the caller's permission or the conversation's current state, so it stops short of full when/when-not guidance.

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