Simulate a swap

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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so safety is covered structurally; the description adds real value by disclosing the execution mechanism (eth_call on your node, implying an RPC dependency) and the return contents ('the plan and the simulation'). It stops short of describing failure/revert behavior.

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, zero filler, with the core action front-loaded and the key non-mutating guarantee placed last for emphasis. Every sentence carries information.

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 read-only, 11-parameter tool with full schema coverage and no output schema, the description is nearly sufficient: it names the mechanism and says what is returned. It omits what a failed/reverting simulation looks like and any chain/version caveats that a caller might want.

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 the schema fully documents all 11 parameters including the amount/amountIn and slippage/deadline semantics. The description only loosely anchors the 'from' parameter ('from the given account') and adds no other parameter meaning, 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 (simulate/dry-run a swap) plus the exact mechanism (eth_call from the given account), which is more precise than the bare name. It implicitly relates to sibling build_swap by saying it 'builds the swap, then dry-runs it', but never names alternatives to route against explicitly.

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 phrase 'dry-run' and 'Nothing is signed or sent' imply the use case (preview before executing), so usage is inferable. However, it never states when to choose this over build_swap or get_quote, nor any preconditions or exclusions.

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