dns_list_blocked

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

No annotations are provided, so the description carries the burden. It discloses the key behavioral trait: the hierarchical tree structure and the two calling modes (top-level vs. drill-in). It could also mention that this is a read-only operation, but 'list' implies it. The added context is meaningful beyond what the schema provides.

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?

Two sentences, front-loaded with purpose, and no unnecessary words. Every sentence adds functional value: first defines what it lists, second explains the drill-down mechanism. Highly efficient.

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 list tool with one optional parameter, the description is quite complete: it explains both call modes and the hierarchical nature of the output. A bit more detail on what each tree node contains (e.g., whether subdomains are shown as strings) would be useful since there is no output schema, but this is a minor gap.

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 coverage is 100% for the single 'domain' parameter. The description adds value by explaining the parameter's role in the hierarchical traversal ('omit for top-level zones, pass domain to list children'), which goes beyond the schema's basic 'optional parent domain' description.

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 states a specific verb and resource: 'List blocked DNS zones (domains that are denied).' It accurately distinguishes the tool from siblings like dns_list_allowed by specifying 'blocked'. The hierarchical tree detail adds further clarity.

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 gives clear usage context for the hierarchical drill-down: 'call with no domain to see top-level zones, then pass a domain (e.g. 'com') to drill into subdomains.' It does not explicitly name alternatives like dns_list_allowed, so it doesn't fully meet the 'when-not' criterion, but it's clear enough for the intended use.

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