MGO — Multi-chain Gas Optimizer

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

The description discloses rate limiting and free access, which are behavioral traits. However, it does not explicitly state whether the tool is read-only or has any side effects, leaving some ambiguity given no annotations are provided.

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?

The description is extremely concise, using two short sentences that directly state the tool's purpose and key constraints. Every word adds value without 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?

For a simple tool with no parameters and no output schema, the description adequately covers what the tool does and what it returns (a recommendation and savings percentage). It could be more explicit about the output format, but it is sufficient for basic agent use.

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?

There are no parameters to document, and the schema coverage is complete. Per the rubric, a baseline of 3 is appropriate since there is no additional semantic detail to provide.

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 the tool's function: recommending the cheapest EVM chain with savings percentage. It is specific to EVM chains and distinguishes itself from sibling tools that likely provide raw gas prices.

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 lacks explicit guidance on when to use this tool versus the sibling get_gas_* tools. It only mentions 'Free, rate limited', which is a constraint but does not help an agent decide between alternatives.

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

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

No annotations are provided, so the description bears the full burden of explaining behavioral aspects. It does mention 'live gas' (indicating network calls) and 'no API key' (suggesting a free tier), but it does not clarify whether the tool has side effects, how it sources data, or how the $0.001 USDC cost is applied. This partial transparency is adequate but not thorough.

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?

The description is compact but a bit dense, covering purpose, example output, usage scenarios, and cost information in three sentences. The cost detail ('$0.001 USDC via x402 on Base') feels tangential to the core function and could be seen as noise, but it does not hinder readability. Overall, it is well-structured and within reasonable length.

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 fully captures the tool's behavior and output. It explains that the tool returns the cheapest chain with savings percentage, provides an example, and specifies when to use it. Since there is no output schema and no parameters, no additional context is needed. The description is complete for an agent to correctly invoke and understand the result.

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?

The tool has zero parameters, so the schema coverage is inherently complete. The baseline score for no parameters is 4, and the description adds no unnecessary parameter details, which is appropriate. There is nothing to clarify about inputs.

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 the tool's function: 'Find the cheapest EVM chain before sending a transaction. Compares live gas across Ethereum, Base, Arbitrum & Optimism and returns the cheapest chain with savings %'. It also provides a concrete example of the output. This makes the purpose unmistakable and distinct from the sibling tools (which likely offer different scopes or pricing tiers).

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 explicitly advises when to use the tool: 'Use before bridging, deploying a contract, or any tx where you can choose the chain.' It also signals its basic/free nature with 'no API key' and mentions a cost ($0.001 USDC via x402 on Base), which helps users decide between this and premium alternatives.

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

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

No annotations are provided, so the description carries the full burden. It discloses rate limiting and free access, but does not mention side effects, error behavior, or data source limitations.

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?

One concise sentence with no filler or redundancy. Includes all essential information: action, resource, scope, cost, and rate limit.

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 simple zero-parameter tool with no output schema, the description is complete: it states what is returned (gas prices), the supported chains, and a key constraint (rate limit). No critical context is missing.

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?

Tool has no parameters and the schema is empty, so there is no parameter information to clarify. The description appropriately focuses on behavior rather than inputs.

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?

Clearly states a specific verb ('Get'), a specific resource ('real-time gas prices'), and the exact scope (4 EVM chains: Ethereum, Base, Arbitrum, Optimism). The name also distinguishes it from sibling tools like get_cheapest_chain and get_gas_basic/premium.

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?

Implies usage through 'free' and 'rate limited 10/hr', suggesting a demo or lightweight tier, but does not explicitly say when to use this tool versus the get_gas_basic, get_gas_premium, or get_cheapest_chain alternatives.

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

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

No annotations are provided, so the description carries the full burden. It mentions the return value (cheapest chain with savings %) and 'no API key' requirement, but it does not clarify side effects, data freshness, rate limits, or what the '$0.002 USDC via x402 on Base' phrase means (likely an example cost or output format, but ambiguous). This lack of detail reduces transparency.

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?

The description is reasonably concise but contains redundancy: 'cheapest EVM chain' and 'cheapest chain' are repeated, and 'widest chain coverage' and 'lowest-fee network' are synonyms. It could be streamlined, but it is not overly verbose.

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 provides enough context to understand the tool's purpose and output (cheapest chain with savings %). It also hints at cost (e.g., '$0.002 USDC') and indicates no API key is needed. However, it omits details about error behavior, data staleness, or how to interpret the output in the context of cross-chain routing, leaving some gaps for a complete picture.

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?

The tool has zero parameters, and the schema coverage is 100% (vacuously). The description does not need to explain parameters, and since none exist, there is no possible confusion. It fully satisfies this dimension.

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 the tool finds the cheapest EVM chain across 9 networks and returns savings percentage, which is specific. However, it does not explicitly contrast with the sibling tool get_cheapest_chain, which appears to serve a similar purpose, leaving potential ambiguity about when to choose one over the other.

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 provides a usage scenario: 'Use when you need the widest chain coverage to route a tx to the lowest-fee network.' This gives some guidance but does not mention alternatives or when not to use this tool, especially given the existence of get_cheapest_chain and other gas-related siblings. It could be more explicit about exclusions.

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