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

Since no annotations are provided, the description carries the full burden and does so admirably. It discloses that every spend was verified on-chain, amounts reflect what the chain showed arrived (not agent-reported), and that Robyn can only account for money moved through Robyn. This is substantial and trustworthy behavioral transparency.

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 moderately sized but every sentence adds distinct value: core definition, usage timing, verification detail, scope limitation, and a presentation warning. It is well-structured and front-loaded with the primary purpose, making it easy to scan.

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 tool with one parameter, no annotations, and no output schema, the description is exceptionally complete. It explains the certificate's contents (spends, budget, total, compliance), its signed nature, the on-chain verification process, and the scope limitation, leaving no major gaps.

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 only parameter, mandateId, is not mentioned in the description. The description references 'a mandate' but does not explicitly map this to the mandateId parameter or explain how to obtain it. With 0% schema coverage, the description fails to compensate, leaving the parameter semantics underspecified.

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 that the tool produces a signed certificate listing every spend counted against a mandate, the budget, the total spent, and compliance status. This specific verb+resource combination distinguishes it from other Robyn tools, especially by emphasizing it certifies adherence to a ROBYN budget, not total spending.

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?

It provides an explicit usage context ('Hand it to the principal at the end of a period') and a clear exclusion: it does not certify that the agent spent nothing elsewhere and should not be described as proof of total spending. This is strong when/when-not guidance, even though no alternative tool is named.

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