WebSocket.connect — open a live WebSocket

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

Goes well past the annotations (which only mark it non-readonly, destructive, open-world, non-idempotent) by disclosing the 200-frame capped ring buffer, OnMessage/OnClose wiring, the open-flag side effect, the type-guard plus pcall wrapping, and the { id, url } vs { error } return shape. It also flags the mutation approval requirement and external socket I/O, which an agent needs before invoking.

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 critical facts (what it opens, the registry id, the downstream siblings) are front-loaded in the first two sentences, and the buffer/pcall behavior follows logically. The trailing block of templated metadata (phase, cost, capabilities, 'On failure: inspect tool-schema...') is partly boilerplate that duplicates annotations, keeping it short of a 5.

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?

There is no output schema, and the description compensates by spelling out the return shape ({ id, url } or { error }) and the id contract used by sibling tools. With annotations covering safety and the schema covering both parameters, nothing an agent needs to call 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 description coverage is 100%, so both url and threadContext are already fully documented in the schema. The description's 'Signature: { url: string, threadContext: number? }' restates the schema without adding format, default, or constraint detail beyond it. Baseline 3 applies when the schema carries the load.

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 — 'opens a real outbound WebSocket from the client via WebSocket.connect(url)' — and explicitly separates itself from siblings by naming ws-send, ws-receive, ws-close, and ws-list as the follow-on tools. An agent can place this as the entry point of the WebSocket workflow without opening any 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 clear operational context: the returned id is what the sibling tools consume, and 'Verify with: ws-list' tells the agent how to confirm success. It also states prerequisites (requires active-client and explicit-mutation-approval). It stops short of saying when NOT to open a socket or naming a competing alternative, so it is clear context rather than explicit routing.

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