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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds meaningful context beyond them: that the call costs nothing and that the catalog is exhaustive ('every route, price, network and pay-to address'), which tells the agent to expect a complete inventory rather than a paginated subset.

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?

Two short sentences with no filler; the cost signal is front-loaded and the content scope follows immediately. Every word 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?

With an output schema present, the description need not explain return values, and for a zero-parameter read-only tool the coverage is nearly sufficient. A brief note on what the catalog is used for (e.g. route discovery or address lookup) would close the remaining gap.

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 takes zero parameters and the schema has no properties, so there is nothing for the description to clarify; the baseline for a no-argument tool applies. The description correctly does not invent parameters or imply any filtering options.

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 names a concrete resource (a catalog of routes, prices, networks and pay-to addresses) and specifies it is machine-readable, so an agent knows exactly what it returns. It does not explicitly contrast itself with the closest sibling, get_pricing, so it stops short of full sibling differentiation.

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 leading word 'Free' implies when to reach for this tool (cost-free discovery versus a paid pricing call), which is useful implied guidance. However, there is no explicit statement of when to use this over get_pricing or what preconditions apply, so the routing logic is left to inference.

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