email_security_posture

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

Beyond annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint), the description adds important behavioral details: passive DNS-only, no SMTP probe, DKIM probing tests common selectors and recent dates, and rate limits (30/hr free, 500/hr Pro). No contradictions with annotations.

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 and well-structured, with five sentences each adding distinct value: resource scope, dual-use, score range, DKIM probing details, passive nature, and rate limits. No wasted words.

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 presence of an output schema, the description sufficiently covers purpose, parameters, behavior, and constraints. It provides complete context for an agent to decide when to invoke this tool, though it lacks explicit differentiation from sibling tools like email_mx.

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% with clear parameter descriptions. The description adds minor nuance by explaining that DKIM probing tests common selectors by default and custom selectors must be supplied via the optional parameter, but this is largely redundant with the schema.

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: analyze domain email authentication posture (SPF, DMARC, DKIM) and produce a numeric score and findings. The verb 'Analyze' with specific resources distinguishes it from sibling tools like email_mx or email_verify.

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 mentions dual-use (red-team and blue-team) but does not explicitly contrast this tool with alternatives or provide when-to-use/when-not-to-use guidance. Usage is implied but lacks explicit exclusions or comparisons.

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