Change zone default TTL

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

Annotations only declare idempotentHint=true, so the description carries most of the behavioral burden. It adds useful context that the change affects only RRSets lacking an explicit TTL, but it does not describe other behavioral aspects such as response, propagation, or whether existing explicit TTLs are preserved.

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 two concise sentences with no wasted words. The main action is front-loaded, and the clarifying scope statement earns its place without redundancy.

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 simple two-parameter mutation tool, the description provides enough context to understand the operation and its scope. The output schema is absent and annotations are minimal, but the description covers the key distinction from per-RRSet TTL changes, making the tool sufficiently understandable.

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 input schema already documents both parameters with 100% coverage, so the baseline is 3. The description adds value beyond the schema by clarifying that the ttl parameter is the default TTL for the zone and applies only to RRSets without an explicit TTL, which gives deeper semantic meaning.

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 clearly states the tool changes the default TTL of a DNS zone, with a specific verb and resource. It also distinguishes itself from the sibling change_rrset_ttl by scoping the change to the zone-level default and clarifying it applies only to RRSets without an explicit TTL.

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 implies when to use this tool: when setting the zone-wide default TTL rather than an individual RRSet's TTL. It does not explicitly name an alternative tool like change_rrset_ttl, but the phrase 'default' and 'without an explicit TTL' gives clear contextual guidance.

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