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

Adds substantial context beyond annotations: 8 KB calldata cap, revert behavior (422 with reason, uncharged), and full pricing model ($0.01/call, first 25 free, failed calls free, repeats not free). That last point reconciles the billing implications of idempotentHint=false, which annotations alone would not convey.

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-loaded with purpose, then limits, then pricing; every line is informative. The pricing sentence is dense and could be split, but nothing is truly wasted for a paid API.

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, and the description compensates by stating the return is raw hex return data that must be decoded with the function ABI. Error behavior, size limit, and cost model are all covered, so an agent has what it needs to call and interpret results.

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 100% and describes all three params, so the schema carries the load; the description still reinforces that data is selector+args and shows a real to/data pair. The optional 'from' parameter (msg.sender checks) is not mentioned in the description, leaving a small 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?

States a specific verb and resource ('read-only contract call ... eth_call', 'send ABI-encoded calldata ... get raw return data') on a named chain. The line 'use to read any view function that has no dedicated tool' lets an agent distinguish it from the dozens of specific avax_* readers without inspecting 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?

Explicit when-to-use: any view function lacking a dedicated tool, with a concrete worked example (USDC totalSupply). It implies the alternative class (dedicated tools) but never names one, and doesn't address when to use avax_call vs the equivalent eth_call/arb_call on another chain.

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