check_fields

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

No annotations are supplied, so the description carries the full disclosure burden. It conveys that the call is non-generating and rule-based, which implies no side effects, but says nothing about permission requirements, what happens when fields are invalid, or whether validation is local or remote. The presence of an output schema covers return values, which limits the penalty.

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?

Two short sentences with the purpose and the timing guidance front-loaded; every clause adds information and there is no filler.

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?

The output schema relieves the description of explaining results, and the purpose plus pre-generation timing are covered. However, for a tool whose only input is an untyped nested object, the description should specify what belongs in 'fields' — that gap is material for correct invocation.

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 single 'fields' parameter is a free-form nested object with additionalProperties=true and 0% schema description coverage, so the schema tells the agent nothing about what keys to supply. The description only gestures at 'application form values' and 'published rules' without naming the expected keys, formats, or required rule identifiers.

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 object ('Validate application form values against the published rules') and adds a negative scope clause ('without generating anything') that separates it from generate_materials and estimate_material. It stops short of naming a sibling explicitly, so it is clear but not fully differentiated.

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?

'Use this to fix fields before a long generation run' gives a concrete trigger, and the 'without generating anything' clause implies the exclusion. It never names an alternative tool or states what to do if validation passes or fails, leaving some routing to inference.

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