check_email_security

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

With no annotations provided, the description carries full burden. It clearly labels the tool as 'Read-only', indicating no mutation, and discloses timing ('~3-8s') and authentication requirements ('No auth'). It also describes the combined nature and output (score, issue list).

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 extremely concise: two sentences plus a summary. It front-loads the main purpose and includes all essential information without any 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 tool's complexity (combining multiple checks), the description is very complete. It lists all checks performed, mentions the output (score and prioritized issue list), gives usage guidance, timing, and auth info. No output schema exists, but the description sufficiently covers what the agent needs to know.

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 sole parameter 'domain' has full schema coverage (100% described in input schema as 'Domain name, e.g. example.com'). The description does not add further parameter-specific details beyond what the schema provides, so baseline 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 it performs a combined read-only email security check including SPF, DKIM, DMARC, MX blacklist, and an aggregated score. It uses the verb 'check' and specifies the resource 'email security', distinguishing it from sibling tools like check_spf, discover_dkim, etc., by stating it replaces sequential calls.

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 tells when to use this tool ('one-shot email security overview') and when not to, providing alternatives: 'use check_sender_requirements for Google/Yahoo bulk-sender compliance, or the individual check_* tools when you need only one signal.'

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