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

With no annotations provided, the description carries the full burden. It discloses that the tool is free, reads live data from the route table, and provides per-call prices and summaries. This gives key behavioral context (no cost, real-time source). It does not mention potential rate limits or response format, but for a simple listing tool this is sufficient.

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 exactly two sentences, with the first sentence packing all relevant information (what the tool returns, the currency, the source) and the second clarifying that it is free. There is no redundancy or filler.

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 zero-parameter, read-only listing tool, the description covers the essential context: what it lists, the price accuracy, the live source, and the free cost. No output schema exists, but the description adequately communicates what the agent will receive. There are no hidden prerequisites or side effects to disclose.

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 input schema is empty (0 parameters), so there are no parameter semantics to clarify. Baselines for 0-param tools is 4. The description adds meaning by explaining the output (endpoints, prices, summaries), which is the only relevant semantic content.

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 what the tool does: it lists every endpoint the server fronts with exact per-call USD pricing and a one-line summary. It differentiates itself from sibling tools by being a meta tool about pricing, not a functional data tool like gas_compare or ens_resolve.

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 implies usage: one would call this to discover endpoint costs before making other calls. It says the prices are read live from the route table and are free, which suggests it is safe to use at any time. However, it does not explicitly say 'use this before calling other endpoints to check costs' or mention when not to use it, 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.