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

With no annotations, the description carries the full behavioral burden and does disclose meaningful traits: statefulness, that output is a delta relative to a baseline, that certificate-expiry signals are included, and that each call costs $0.01 USDC on Base. It omits rate limits, baseline retention/expiry, and failure behavior when no baseline exists.

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 dense sentences with zero filler: capability first, then the stateful lifecycle, then cost. Every sentence carries new information and nothing is repeated from the name or title.

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 one-parameter tool with no annotations and no output schema, the description covers what it watches, the baseline/delta model, the kind of signals returned, and the price. The remaining gap is operational detail such as baseline lifetime and behavior on the very first versus subsequent invocations under failure.

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 'domain' parameter has 0% schema description coverage, so the description must compensate. It adds one qualifier — the domain must be public — but gives no format, TLD scope, or normalization rules, leaving the schema gap only partially filled.

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 names a specific verb-and-resource: stateful DNS, CAA, and certificate-transparency monitoring for a public domain. An agent knows exactly what the tool observes. It does not, however, contrast itself with siblings like sec_material_event_delta or mcp_vendor_due_diligence, so differentiation is left to inference.

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 explains the invocation lifecycle ('first call establishes a baseline; later calls return evidence changes'), which tells the agent this is a repeated-call tool rather than a one-shot lookup. There is still no explicit when-to-use versus an alternative, no prerequisite (e.g. domain must already resolve), and no when-not guidance.

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