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

With no annotations, the description fully discloses behavioral traits: the output is a 'RECORD, not a guarantee', may be stale ('does not promise the same capability a minute later'), and the signature does not imply an SLA. It also clarifies the meaning of `notServiceable`. This is substantial transparency beyond any possible annotation.

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 front-loaded with the core purpose, then layered with usage instructions, field clarification, and limitation caveats. Each sentence earns its place: the field emphasis, the fallback explanation, and the non-SLA disclaimer are all necessary for correct use. No fluff.

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?

Despite having no output schema and no annotations, the description provides a comprehensive picture: what the tool returns (capability categories), how to use the key field (`serviceableNow`), what `notServiceable` contains, and critical caveats (not a guarantee, may change). This is sufficient for an agent to decide when to call it and how to interpret results.

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, so the schema offers no parameter details. The description compensates by explaining output fields like `serviceableNow`, `policyEligible`, and `notServiceable`, adding semantic meaning even though these are not parameters. A 4 is appropriate given the baseline for zero parameters.

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 the tool produces 'a signed, timestamped record of current capability' and enumerates exactly what it covers (chains payable now, policy-eligible chains, execute-ready rails, delivery estimation). This goes beyond a simple verb+resource and clearly distinguishes it from sibling tools like robyn_quote or robyn_preflight by focusing on current operational capability.

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?

Explicit guidance is given: 'USE serviceableNow, NOT policyEligible, when deciding where to send funds' with a concrete explanation of why (policy eligibility may not reflect inventory). It also instructs to 'Fetch this BEFORE committing to a multi-step plan' and explains the evidence value. This is direct, actionable usage context.

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