evm_chainsLive health of every supported chain in one call: chain id, block height and how stale the head is. Use it to pick a chain that is actually responding. Flat $0.001 per call, paid over x402 (USDC).
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the full burden. It discloses pricing (flat $0.001 per call) and payment method (x402/USDC), which adds transparency. It does not explicitly state the operation is read-only, but the nature of a health check makes that implicit.
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 concise, with no unnecessary words. It efficiently communicates purpose, output, and usage in two sentences.
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?
Given there is no output schema, the description sufficiently describes what the tool returns (chain id, block height, staleness) and includes pricing info. It is complete enough for a user to understand the tool's function.
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, so the baseline applies. The description does not need to explain parameter behavior since none exist.
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 provides live health data for all supported chains, listing specific outputs (chain id, block height, staleness). It is distinct from sibling tools like evm_balance or evm_block.
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?
It explicitly suggests the primary use case: 'Use it to pick a chain that is actually responding,' giving actionable guidance on when to invoke this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.