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

With no annotations, the description carries the full burden, and it does disclose meaningful behavior: parallel checks against 3 independent providers and the consensus rule ('only signs an attestation if all agree'), plus the cost model. It omits what happens on disagreement (error vs partial result) and any rate limits, keeping it short of a 5.

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?

Core function and consensus rule are front-loaded in a tight first clause. The second sentence is somewhat promotional (plugging a paid URL) but still conveys a legitimate routing fact, so it mostly 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?

For a simple one-param oracle with no output schema, the description covers purpose, consensus behavior, and cost. It stops short of describing the returned attestation's shape or the disagreement outcome, which an agent would need for robust use, but the gap is modest.

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% and the single parameter is fully documented there, so the baseline is 3. The description adds only the chain scoping ('Base tx hash'), which is a marginal gain over the schema's generic '32-byte transaction hash'.

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?

States a specific verb+resource ('Checks a Base tx hash') and the distinguishing mechanism ('3 independent RPC providers in parallel'), which cleanly separates it from the sibling verify_tx. An agent can tell what this does without opening the schema.

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 implies a free-vs-paid usage split ('Free via MCP; ... also available pay-per-call ... for production/agentic use'), giving some routing context. However, it never states when to choose this over the sibling verify_tx or any other alternative, so usage is only implied.

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