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

Annotations already establish readOnly/openWorld/idempotent/non-destructive behavior. The description adds value beyond those by specifying determinism, the comparison-and-report behavior, and the paid resource cost ($0.002 USD per call). It does not describe error behavior or output shape, but for a safe, read-only comparison tool the added context is meaningful.

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?

Three sentences, no filler: the core function comes first, then intended use and exclusions, then cost. Every sentence earns its place and the most decision-relevant constraints are front-loaded.

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 no output schema and no parameter descriptions, the definition is too thin to fully support correct invocation. It omits how verification rules map to parameters, what a 'material difference' means, and what the response contains, so an agent cannot confidently construct a correct call beyond passing expected and observed.

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 0%, so the description carries the burden of explaining parameters. It names 'expected' and 'observed' but only vaguely references 'caller-supplied verification rules.' It never explains ignore_paths, required_paths, or numeric_tolerance semantics, path syntax, or how tolerance is applied, leaving the agent under-informed for a 5-parameter tool.

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 uses a specific verb-resource pair: it 'deterministically compares caller-supplied expected and observed values' and 'reports material differences.' It also narrows the intended context to trust identity permission / trust unknown, which separates it from the many verification siblings and unrelated adjudication tools.

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 gives an explicit positive context ('Intended for trust identity permission / trust unknown') and explicit exclusions ('Do not use for legal, identity, sanctions, fraud, contractual, or regulatory adjudication'). However, it does not name a specific alternative tool to route to when those exclusions apply, so it stops short of full alternatives guidance.

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