Pick, hover, or ban champion in champion select

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

Annotations already flag destructive=true and idempotent=false, but the description adds meaningful context beyond them: 'A lock-in cannot be undone' and the required write allowlist entry ('PATCH /lol-champ-select/v1/session/actions/*'). It doesn't cover failure modes or timing constraints in champ select, keeping it short of a 5.

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 core action, then usage, then alternatives, then the safety/permission notes. Slightly dense with three sibling references and a raw endpoint path, but each sentence carries distinct information.

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 destructive mutation tool with no output schema, it covers the essentials: what it does, when to use it, what it irreversibly changes, and the permission prerequisite. An agent has everything needed to invoke it correctly.

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 the schema fully documents type, champion, and completed. The description's 'by name or ID' and 'hovers or locks in' merely restate what the schema already says, so the baseline 3 applies.

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 specific verbs and resource: 'Resolves local player action in active champion select, chooses champion by name or ID, and hovers or locks in.' It clearly distinguishes itself from the sibling bench tool and other workflow tools.

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?

Explicitly says when to use it ('during draft or blind pick phases to hover or confirm champion selection or ban') and names alternatives for adjacent needs (lol_workflow_runes_set for rune pages, lol_workflow_lobby for lobby management), plus a directive to prefer it over manual REST/lol_eval.

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