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

Annotations already declare readOnly=false, destructive=false and idempotent=true, so the safety profile is covered. The description adds real behavior beyond that: outcome closes the flow early without marking steps done, and the same idempotency_key must be reused on retries. Missing is any statement of required permissions or what happens to unfinished steps in the normal path.

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?

Four short sentences, front-loaded with the core action, then parameter guidance, then the retry rule. Dense and useful, with no filler, though the flow chip analogy costs a clause an agent may not need.

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 5-parameter mutation tool with no output schema, the description covers the action's variants, the disambiguating parameter, and retry idempotency. The main residual gap is outcome/permission behavior and what response to expect, which no output schema fills in.

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 only 20% (only idempotency_key is described in the schema), so the description carries most of the burden. It explains conversationFlowId's disambiguation role, outcome's early-close semantics with an example, and that close_note is optional; only conversation_id is left unstated, and it is self-evident.

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?

Specific verb+resource: 'Marks a conversation's flow done', with an analogy to the UI flow chip's Mark done. This separates it from remove_conversation_flow and start_conversation_flow by implication, though it never names those siblings explicitly.

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 conditional guidance — supply conversationFlowId when the thread has more than one flow, and use outcome to close early without completing steps. It does not say when to prefer this over remove_conversation_flow, edit_flow, or set_conversation_status, leaving the alternative selection to inference.

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