validate_email

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

With no annotations, the description transparently states it validates syntax and TLD but not deliverability. It does not mention side effects or network calls, but for a validation tool this is adequate.

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 front-loaded with the action prompt. No wasted words; every sentence adds value.

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?

The description covers purpose and limitations well, but lacks information about the output format (e.g., boolean, object). Given no output schema, 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% with a basic description. The tool description adds value by explaining the validation scope (syntax and TLD), going beyond 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: to validate an email address's syntax and check that the domain TLD is real. It distinguishes itself from sibling validation tools by focusing on email-specific checks and specifying RFC standards.

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?

Explicitly says 'USE THIS to check... before saving or sending — instead of trusting raw input.' Also clarifies what it does NOT do (deliverability), guiding the agent on when not to use it.

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