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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds behavioral context beyond these by detailing that the tool traces DS/DNSKEY records and algorithm usage at each zone level, and implies per-zone walking. No contradictions are present (annotation_contradiction=false).

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 only two sentences long, with no filler or repetition. The first sentence front-loads the core purpose (walking the chain with specific records). The second sentence provides clear usage guidance. Every sentence earns its place.

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?

Given the tool has an output schema (so return values are documented), three well-documented parameters, and comprehensive annotations, the description is nearly complete. It covers purpose, scope (zone-level tracing, algorithm usage), and usage guidance. One minor gap: it doesn't mention potential time or network requirements, but that is often implied and not critical for selection. Overall, it's adequate for confident agent 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?

Schema description coverage is 100%, so all three parameters (domain, format, force_refresh) are already documented in the input schema. The description does not add extra semantic detail for the parameters beyond what the schema provides. A score of 3 is appropriate as the schema carries the full burden, and the description adds minimal parameter-specific value.

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 ('Walk') and clearly identifies the resource ('full DNSSEC chain of trust from the DNS root down to the target domain'), including the records traced (DS/DNSKEY) and algorithm usage. It distinguishes itself from siblings like check_dnssec (general validity) and check_dnskey_strength (key strength) by focusing on step-by-step delegation path tracing.

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 states when to use the tool: 'when asked to trace the chain of trust from the DNS root, or to see the full DNSSEC delegation path step by step.' This provides clear context. While it does not explicitly mention when not to use it or list alternative sibling tools, the usage scenario is specific enough to guide an agent.

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