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

No annotations are provided, so the description carries the whole burden. It usefully discloses that the tool is free and requires no payment, and what fields come back per match, but says nothing about ordering, how far back 'recent' reaches, pagination, or rate limits. The presence of an output schema absorbs some of the return-value burden, keeping this at a mid score.

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?

Three short sentences, front-loaded with the [FREE] marker and the core action, with the sibling routing placed after. The closing 'No payment required' restates the [FREE] tag, a minor redundancy, but nothing is bloated.

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 simple read-only list tool with one optional scalar parameter and an output schema, the description covers what it returns and points to the sibling for single-match detail. The only real gap is the undocumented limit/pagination semantics, which is modest given the output schema exists.

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 one optional parameter (limit, default 10) at 0% schema description coverage, and the description does not mention it at all. The name is largely self-explanatory, but with zero coverage the description should have added bounds or behavior (e.g., max limit) and it does not.

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?

Specific verb (List) plus a precisely scoped resource (recently anchored AIARENA match replay proofs), and it states the payload returned (IPFS CID + Base anchor tx per match). It explicitly distinguishes itself from the sibling aiarena_replay_proof, so an agent can route without opening a 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?

Names the alternative tool and the condition that selects it: use aiarena_replay_proof(mid) when you want the full proof bundle for one match. This implies the bulk-listing use case for this tool, but it never states the reverse condition explicitly (use this tool when browsing many matches rather than one).

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