m2m_get_gas_metrics

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds valuable context beyond annotations: 'RPC provenance for the upstream observation' indicates the data source, and the explicit exclusions (no contract inspection, no token/DEX pricing, no transaction authorization) clarify boundaries. This enriches the behavioral model without contradicting annotations.

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 two sentences with no redundancy. The primary purpose is front-loaded in the first sentence, and the second sentence provides necessary exclusions. Every word adds value; there is no filler or repetition.

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 read-only telemetry tool with no parameters and no output schema, the description covers everything an agent needs: what it returns (gas price with units), where data comes from (RPC provenance), and what it explicitly does not do (inspect contracts, return pricing, handle transactions). No additional details like pagination or authentication are necessary for this scope.

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 schema coverage is 100% (empty schema). The description does not need to explain parameters. Per the baseline for 0-parameter tools, a 4 is appropriate. It adds no parameter-specific info because none exist, but it does clarify output units (wei/gwei), which is useful context for interpreting results.

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 a specific verb ('Fetch') and resource ('current Base gas price') with units (wei/gwei). It also explicitly distinguishes itself from sibling tools by listing exclusions: 'does not inspect contract code, return token/DEX pricing, or authorize or submit transactions.' This makes its purpose unambiguous and differentiates it from m2m_audit_contract, m2m_get_token_price, m2m_get_dex_liquidity, and m2m_get_whale_signals.

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 clear context for when to use the tool: whenever a current gas price is needed. It gives negative guidance by stating what it does not do (inspect contract code, return pricing, authorize transactions), which implies those tasks belong to other tools. However, it does not explicitly name sibling alternatives or state conditions for choosing this tool over them, so it falls just short of a 5.

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