check_subdomailing

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, covering safety and behavior. The description adds that the tool analyzes the SPF include chain for dangling subdomains, which is behavioral context beyond annotations. No contradictions.

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-loading the core purpose. Minor redundancy exists between the first sentence and the usage guidance, but it remains efficient and clear overall.

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 annotations, output schema (present), and 100% schema coverage, the description covers the tool's behavior, use case, and relation to scan_domain audit. It does not need to explain return values due to output schema, making it complete for an AI agent.

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 the description does not need to add parameter details. However, it provides no additional semantics beyond the schema, such as how force_refresh relates to DNS changes or format differences. Baseline score of 3 is appropriate.

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's purpose: 'Detect SubdoMailing risk' by analyzing SPF include chains for dangling or hijackable subdomains. It specifies the resource (SPF include chain) and the action (detect risk), and distinguishes it from sibling tools focused on other DNS checks.

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 says 'Use when you want to know if an SPF include chain can be hijacked...' which provides clear guidance. However, it does not mention when not to use or list alternative tools explicitly, though the sibling list hints at other options.

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