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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds one useful behavioral fact, the UTC-day unlock gate, but says nothing about what happens when a replay is still locked (error vs empty), nor about pagination or size of the returned states.

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?

Two short sentences, front-loaded with the action and followed by the gating rule; there is no filler. It could arguably be a touch more specific without becoming verbose, but nothing in it is wasted.

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?

With no output schema, the description should characterize the return value, and 'saved states' remains vague (states of what, at what granularity). For a read-only single-param tool it is minimally viable, but the locked-replay behavior and result shape are left to inference.

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?

There is a single required resultId with 0% schema description coverage and no pattern documentation in the description. The phrase 'for a published result' loosely ties the parameter to a published result ID, which is marginal added meaning over the bare schema.

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 (read) and resource (saved states for a published result), and the title adds 'public game replay'. It is clear what the tool does, but it never distinguishes itself from the sibling arcade_read_game, which an agent could easily confuse with this one.

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 description implies usage via the unlock rule ('Daily replays unlock after the UTC challenge day ends'), which is a genuine precondition. However, it gives no explicit when-to-use vs when-not guidance and never names an alternative sibling tool for reading live/ongoing games.

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