transaction_simulate

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds valuable behavioral details beyond annotations: it uses RPC trace when available and falls back to static decoding for token balance changes. This explains the execution mechanism and output focus, though it doesn't specify failure 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?

A single, well-structured sentence that front-loads the primary action and method, with no redundant words. Every phrase earns its place by conveying the simulation approach and fallback behavior.

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?

The description covers the core purpose and simulation method, but since there is no output schema, it does not explain the return format or how to interpret results beyond mentioning token balance changes. Given the tool's moderate complexity and read-only nature, this is a noticeable gap but not critical.

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%, with all five parameters (chainId, to, data, from, value) described in the schema. The description adds no additional parameter-level explanation, but it does clarify that the output relates to token balance changes, which is indirectly useful. Baseline of 3 applies because the schema carries the load.

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 identifies the tool as simulating an unsigned transaction, with a specific verb ('Simulate') and resource ('unsigned transaction'). It also distinguishes itself from sibling tools like transaction_confirm/transaction_deny by emphasizing the simulation aspect, and from read tools like evm_read_contract by focusing on transaction execution simulation.

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 description states the core use case (simulating an unsigned transaction) and hints at a fallback behavior, but does not explicitly state when to choose this tool over alternatives or mention any exclusions. Context implies it is for pre-signing preview, but there is no explicit 'use this instead of X' guidance.

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