Start buffering LCU events

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

Annotations already disclose the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=true), and the description adds substantial behavioral context beyond them: in-memory ring-buffer eviction, the fact that calling while running updates URI filters and preserves buffered events, and the client-running prerequisite.

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 description is front-loaded with its core purpose, then proceeds through usage, alternatives, behavior, and prerequisite in a dense but well-structured way. Every sentence provides routing or behavioral value, and there is no filler.

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 one-parameter start-buffering tool with no output schema, the description covers what the tool opens, what it buffers, how to consume the buffer, competing alternatives, ring-buffer limits, update behavior, and the client prerequisite. Nothing material is missing for correct invocation.

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 filter parameter's syntax and default behavior are already documented. The description still adds meaning beyond the schema by clarifying that calling while running updates URI filters without discarding already buffered events, which is a useful lifecycle detail for that parameter.

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?

The description states a specific verb and resource: opening the League Client WebSocket event tap and buffering live OnJsonApiEvent Create/Update/Delete notifications. It explicitly distinguishes this tool from lol_events_poll, lol_wamp_record_start, and lol_static, so an agent can route correctly without opening sibling schemas.

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?

It gives clear when-to-use guidance for monitoring real-time client state changes and names concrete examples such as champ select, gameflow, and lobby updates. It also routes agents to alternatives for polling, raw WAMP recording, and static assets, and states the prerequisite that the League client must be running.

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