validate_dnssec

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true. The description reinforces 'Read-only' and states 'Single HTTP GET, no auth, no destructive actions,' which aligns with annotations. It adds context about the specific behavior (chain walking, result types) beyond annotations, but since annotations are comprehensive, a 4 is appropriate rather than 5.

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 concise, front-loaded with the key purpose, and every sentence adds value: says what it does, what it returns, when to use it, and alternatives. No redundant fluff.

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 tool is simple with one parameter, comprehensive annotations, and no output schema. The description fully covers the tool's purpose, behavior, usage, and alternatives. It does not explain exact return format but that is not required given no output schema and a simple boolean output. A 4 is appropriate because it covers the key aspects without any significant gaps; a 5 might be overkill given no output details, but this is a high-quality description.

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%, and the only parameter 'domain' has a clear schema description. The tool description adds a bit of context ('Domain name only') but that is shared with schema. The description implies the parameter is a domain name but does not add much beyond schema, so baseline 3 is correct.

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 starts with 'Read-only DNSSEC chain validation' which is a specific verb and resource. It goes beyond mere names to explain exactly what the tool does: walks DS/DNSKEY chain, checks signatures, algorithm strength, key rollover state, and mentions outputs. This clearly distinguishes it from siblings like lookup_dns and check_tlsa_dane.

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 provides explicit usage guidance: 'Use when a domain claims DNSSEC; use lookup_dns(type='DNSKEY') for raw key data only.' This directly tells the agent when to use this tool and points to an alternative for a different purpose, making the distinction explicit.

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