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

The description adds substantial behavioral context beyond the annotations. It discloses that the tool is destructive (can disable the relay) and idempotent (setting config replaces existing). It includes submission details (endpoint, content type, field constraints, rate limits, honeypot), which are not captured in annotations. This helps the agent understand side effects and constraints.

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 front-loaded with the main purpose and is well-structured into logical sections. However, it is relatively long and includes some details (e.g., submission format, rate limits) that could be considered beyond the tool's core responsibility. Still, it remains focused and each 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?

Given the tool's complexity (many config options, multiple behaviors like enabling/disabling, SMTP relay, branding), the description is remarkably complete. It covers when to use it, required roles, follow-up steps, submission details, and response format. The output schema is not shown but the description summarizes the response structure, making the tool self-contained.

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 input schema is fully described (100% coverage), so the schema already provides detailed parameter explanations. The description adds value by explaining the effect of passing null for config and linking the sender configuration to the verification workflow. While the schema covers individual fields, the description provides higher-level context for the most important behaviors.

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: 'Configure the built-in form-to-email relay, fully self-service.' It distinguishes from siblings like get_forms_config and verify_forms_sender_domain by specifying its role in enabling, updating, or disabling the relay. The verb 'configure' plus the resource 'forms relay' is specific and actionable.

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 provides clear guidance on when to use the tool, including the required team role (owner or admin) and how to disable the relay (pass config:null). It also explains a follow-up action (call verify_forms_sender_domain) when setting a custom sender without an SMTP relay. However, it does not explicitly state when not to use this tool or compare it to siblings like get_forms_config for reading.

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