aethis_validate_fields

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

Annotations cover the safety profile (readOnly, non-destructive, openWorld), but with no output schema the description carries the return-value burden and does so thoroughly: it enumerates the diff categories (missing, type mismatch, enum mismatch, extra) and defines the all_match condition including the edge case that extra fields do not affect it. This is substantive behavior disclosure beyond the annotations.

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?

Six tightly packed sentences, front-loaded with what the tool asserts and the all_match contract, followed by sequencing guidance. Each sentence carries distinct information (return shape, success condition, edge case, precondition, failure path) with no repetition.

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 two-parameter read-only assertion tool with no output schema, the description supplies everything an agent needs: the precondition (after discovery), the success criterion, the meaning of extra fields, and the remediation call on failure. Nothing material is missing.

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 coverage is 100%, so expected_fields, key, sort, and enum_values are all documented in the schema itself. The description references an 'expected field specification' but adds no syntax or value-format guidance beyond that, so the baseline 3 for fully-covered schemas applies.

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 resource ('Assert that the discovered fields match an expected field specification') and clearly positions the tool as a verification step distinct from discovery and refinement siblings. The phrase 'discovered fields' and the field-spec language differentiate it from aethis_validate_sections without opening either schema.

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 when-to-use ('Run after aethis_discover_fields to verify field coverage before writing test cases') and explicit next step when it fails ('call aethis_refine_fields with guidance about the missing or incorrect fields'). Both the trigger and the alternative are named, leaving nothing to inference.

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