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

With no annotations, the description carries the behavioral burden. It usefully discloses aggregation behavior ('in one call') and pricing ($0.002), and the operation is implicitly a read-style query. It does not disclose defaults for omitted chains, authentication needs, or failure behavior, but the core behavior is reasonably clear.

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 front-loaded sentence with no filler. Every element—scope, chains, aggregation benefit, and cost—earns its place.

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 output schema may cover return values, but the description still leaves the agent guessing about how to specify chains, whether agent_id is needed, and what the default behavior is. Given the optional parameters and the existence of a similar single-chain sibling, more context is needed for confident invocation.

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 0%, so the description must compensate for both parameters. It only hints that 'chains' relates to the four named networks and says nothing about accepted value formats, defaults, or the purpose of agent_id. This leaves a significant semantic gap.

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's function: returning gas and transfer cost data across ethereum, base, arbitrum, and optimism in a single call. It lacks an explicit verb like 'get' or 'estimate' and does not name a sibling tool, but the scope and resource are unambiguous.

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 'in one call' phrasing implies this tool is for multi-chain gas and transfer cost queries. However, it provides no explicit guidance on when to prefer this over the sibling ddg_eth_gas, no exclusion criteria, and no mention of what happens when the optional chains parameter is omitted.

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