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

Annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds valuable context beyond those annotations: the tool is free/no-payment required, should be called before paid operations, and exposes readiness and public transparency URLs. This complements the annotation safety profile without contradicting it.

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 compact but information-dense: it front-loads the free/no-payment nature, lists the exact facts returned, states the mandatory usage point, and gives an exclusion. Every phrase earns its place with no 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?

With no input parameters and no output schema, the description still enumerates the returned facts in enough detail to set expectations. It also covers the critical sequencing requirement and the tool's non-application to market data or attestation, making it effectively complete for this simple info tool.

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 complete, so no parameter documentation is needed. Baseline for zero parameters is 4, and the description adds enough surrounding context to make invocation straightforward.

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 resource as gateway facts and prices, enumerating specific contents (network, payee, attestor, prices, readiness, ledger, transparency URLs). It explicitly separates itself from market data and attestation, which distinguishes it from sibling tools like get_market_signal and attest_agent.

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 gives an explicit timing instruction: 'MUST be invoked before the first paid call from a new agent.' It also provides clear negative guidance: 'Do NOT use for market data or attestation,' which helps an agent choose this tool over alternatives.

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