Guardian — Human-Verified Approval ($3.00)

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

With no annotations, the description carries full burden. It discloses return outcomes (approved/pending_human/denied), cost ($3.00 USDC on Base), and human-in-the-loop accountability. Lacks details on side effects or prerequisites, but sufficient for a non-destructive approval tool.

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?

Four sentences, each earning its place: purpose, usage context, return values, and unique value proposition (human-in-the-loop + cost). Front-loaded with the core function. No wasted words.

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 no output schema, description explains return outcomes and cost. Does not cover error cases or prerequisites (e.g., having a USDC balance), but adequately sets expectations for an approval 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?

Schema description coverage is 100% with clear parameter descriptions. The tool description adds no extra meaning beyond the schema, so baseline 3 is appropriate.

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 'HUMAN-VERIFIED approval for an agent action' with a specific verb and resource. It distinguishes from sibling tools (all data lookups or extraction) by being the only approval/action tool.

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?

Explicitly says 'Before an agent pays, signs, or acts for its human' which clarifies when to use. Does not explicitly state when not to use, but context from siblings implies it's for actions needing human sign-off, not data queries.

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