HALOWERK: Check tool arguments against their schema before an expensive or irreversible ca

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

The description discloses the two-stage behavioral process (schema validation and heuristic warnings) and importantly notes that warnings can be wrong in both directions, which is critical for interpretation. This goes beyond the readOnlyHint annotation by explaining how results should be used. It also adds pricing and x402 payment details, providing operational context.

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 its main purpose, but it contains redundant pricing information in both German and English, duplicating the same cost details. The structure is organized around the two checks, but the repetition and mixed-language content reduce efficiency.

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 5 parameters and no output schema, the description adequately covers its purpose, behavioral details, limitations, and usage context. It explains what the tool does, when to use it, and its caveats. It doesn't detail the return format, but this is acceptable given the absence of an output schema and the presence of annotations.

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 schema already has 100% coverage with descriptions for all 5 parameters, so the baseline is 3. The description adds value by explaining that fields suggesting irreversible effects are held to stricter standards, which gives additional meaning to parameters like 'irreversible' and helps the agent understand how field names might trigger heuristics. This slightly enhances the schema's semantics.

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's function with a specific verb ('Check') and resource ('tool arguments against their schema'). It also adds the usage context of expensive/irreversible calls, which distinguishes it from sibling tools like output_validate.

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 explicitly says to use it 'before an expensive or irreversible call,' providing clear usage context. It also includes a caution that warnings are heuristics and not a substitute for the tool's own checks, which implies when not to fully trust it. However, it does not explicitly name alternative tools or state strict exclusion criteria.

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