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

Annotations already declare readOnly, idempotent, non-destructive. The description adds substantial behavioral context beyond them: Pro API token requirement (Authorization: Bearer arb_…), unavailability on the anonymous tier, and the exact cost components netted out (aggregator price impact, swap gas, transfer gas, withdrawal fee). It does not disclose rate limits, pagination, or result ordering.

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?

Information density is high and the criteria are front-loaded, but the text is a single run-on sentence with awkward fragments ('status and reasons. Pro.'), where 'Pro' is unclear and duplicates the subsequent auth sentence. It could be restructured without losing content.

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 does explain what comes back (profit at $1k/$5k/$10k, status and reasons), and it flags the auth prerequisite. The only meaningful gap is the unexplained 'base' parameter, which matters for correct invocation.

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 only 50%: 'base' is documented merely as 'Token (optional)' and 'limit' has no description at all. The description adds nothing about what 'base' selects (base currency? base token?) or how it interacts with the scan, so it fails to compensate for the coverage gap.

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 clearly states a specific verb+resource: a scan for tokens with verified contracts across five named chains whose DEX price is >1% away from the exchange price. The qualifying criteria (net profitability thresholds) make the purpose concrete. It does not, however, name or distinguish itself from plausible siblings like best_opportunities or spread_chart.

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 inclusion criteria (>1% gap, verified contract, listed token) imply when results appear, and the Pro-gating sentence tells the agent it needs a Pro token. But there is no explicit when-to-use guidance versus alternatives such as best_opportunities or execution_cost, and no statement of when to avoid this tool.

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