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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely new context — no API key, no signup for the x402 route, and what the response contains. It doesn't state the response format (text vs. structured), which is the one behavioral detail left implicit.

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?

Three tight sentences, purpose first, trigger second, payload content third — well front-loaded with no filler. Minor redundancy between 'what is available without credentials' and 'No API key required' keeps it from a 5.

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 output schema, the description carries the burden of explaining return content and does so at a category level (free-tier capabilities, example inputs, x402 route, registry path). The omission is the response format, which matters slightly more here precisely because there is no output schema.

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?

Zero parameters, so the baseline is 4 by rule. The description reinforces this implicitly by noting that no credentials or setup inputs are required, leaving nothing for an agent to guess.

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 and resource — it explains how to start using Strale — and clearly separates itself from the operational siblings (balance, execute, search) by being the onboarding entry point. An agent can identify this as the first-call tool without consulting any 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?

'Call this on first connection' is an explicit, unambiguous trigger condition, which is more than most definitions offer. It stops short of naming when-not-to-call or explicitly routing to a sibling afterwards, so it lands at 4 rather than 5.

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