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

With no annotations, the description carries the full burden and does so thoroughly: it discloses the simulation method (buy-then-sell round trip inside one eth_call via the pool hook, nothing spent), the ERC-20-USDC fallback (both legs quoted), and what gets returned. It also reveals the critical pricing behavior — $0.025/call over x402 and, crucially, that over MCP the tool returns the price/URL rather than the data.

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 the core purpose and the exclusion ('not a score') before alternatives and payment details. Dense and information-rich, though the conversational framing ('If I put in this much, can I get out?') and 'The answer names its method' add slight redundancy.

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?

No output schema exists, so the description must describe returns — and it does, enumerating pass/fail, round-trip cost, depth, liquidity-pull risk, and flags with reasons. Combined with the payment/MCP-return caveat, an agent has everything needed to call and interpret this tool 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 both parameters (usdc, query) are already fully documented with types, defaults, and format constraints. The description restates the size ('usdc, default 1') and address formats but adds no syntax or semantics beyond the schema, 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 a specific verb and resource ('SELL TEST AT YOUR SIZE... can I get out?') and explicitly distinguishes itself from the scoring tool ('not a score'). Names the two sibling alternatives (arc_verdict, arc_exit_check_bulk) so an agent can disambiguate without opening schemas.

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?

Gives explicit when-to-use routing: 'For one 0-100 buy score with no size needed, use arc_verdict. For up to 25 tokens in one call use arc_exit_check_bulk.' Also scopes the tool to Arc and to token addresses / v4 pool ids, leaving nothing to inference.

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