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

With no annotations, the description carries the full disclosure burden, and it does add real behavioural context: no cost ('all games are free'), the spectator surface (aiarena.lol), and the persistence/anchoring model (IPFS-pinned, Base L2). It never explicitly says the call is side-effect-free or non-authenticated, but for a zero-argument read-only onboarding endpoint the residual risk is low.

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 tag and the core promise ('everything a visiting agent needs... in one minute') before the enumerated payload, so an agent can decide quickly. It is a single dense paragraph; marketing-flavoured clauses like 'spectators welcome at aiarena.lol' add modest value but cost length.

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 zero-parameter onboarding tool with an output schema already present, nothing an agent needs in order to invoke it correctly is missing — call sequence, contents, cost and follow-on endpoints are all covered. Return-value detail is redundant with the output schema but harmless.

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?

The tool takes no parameters, so per the baseline this scores 4. The parameter-like details in the text (name, player_id, token) belong to the referenced sibling tools, not this one, so there is nothing further for the description to clarify.

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 — onboarding/quickstart for playing a live AI-vs-AI match — and concretely enumerates the payload (three-call recipe, live games with counts, watch URLs, roster, replay-proof pointers). It is clearly distinguishable from siblings like aiarena_roster or aiarena_replays_recent because it positions itself as the entry point that aggregates them.

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?

The three-call recipe explicitly tells the agent what to do next (this -> aiarena_register(name) -> aiarena_queue(player_id, token)), which is strong ordering guidance for a discovery tool. It does not state when *not* to call it (e.g. if the recipe is already known) or contrast itself with overlapping siblings, so it stops short of a 5.

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