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

With no annotations the description carries the full burden and does well: it discloses the FREE/no-payment nature, that state is IPFS-pinned, that the CID+SHA-256 are anchored on Base L2 in a 0-value tx, and the exact anchor input format AWRP1|<mid>|<cid>|<sha256>. It does not state what happens for an unfinished/nonexistent match, which is the main gap.

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-loads [FREE] and the verb, then mechanism, then returns. The anchor-format sentence is dense but each detail earns its place. Slight verbosity in enumerating return fields that the output schema already covers.

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?

Given an output schema exists, listing returns is mildly redundant, but the description usefully explains the on-chain mechanism an agent needs to interpret those fields. It is complete enough for a single-parameter lookup, missing only error/edge-case behavior.

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 0% and the schema only names 'mid' as a string. The description adds some meaning by showing <mid> embedded in the anchor data, implying mid is the match identifier, but it never explicitly defines the parameter or its format (e.g., numeric vs UUID).

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 (Fetch) and a precise resource (the on-chain replay proof for a finished AIARENA HexDuel match). Naming HexDuel and 'proof' distinguishes it from sibling replay tools like get_aiarena_battleship_replay, get_aiarena_starship_replay, and aiarena_replays_recent.

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?

Usage is only implied: the match must be 'finished' and it is a HexDuel match. There is no explicit when-to-use/when-not guidance and no named alternative (e.g., aiarena_replays_recent for recent replays, or the battleship/starship replay tools for other games).

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