Smartlead: add domains to the block list

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

The description goes well beyond the annotations by disclosing that it 'creates remote state', is 'blocked in readonly mode', and 'does not send email'. It also states it is non-destructive. These facts align with annotations and add valuable operational context.

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 purpose and uses small, readable sections. However, there is redundancy: the 'Safety —' line duplicates the later statements 'Creates remote state' and 'Does not send email'. This prevents a higher score.

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?

Together with the rich input schema and output schema, the description covers purpose, safety profile, endpoint, and suppression semantics. It is sufficient for correct invocation, though it could optionally mention auth or rate limits.

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 schema already provides 100% coverage of parameters, so the baseline is 3. The description adds meaningful context by emphasizing 'global block list' and 'no campaign emails them', clarifying that the domain_block_list parameter applies across all campaigns, not just a single campaign.

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 action: 'Add domains or email addresses to the global block list so no campaign emails them.' It specifies the verb, resource, and effect, and clearly distinguishes the tool from its siblings like get_domain_block_list and remove_domain_from_block_list.

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 makes the use case clear: use it to suppress outbound emails to certain domains/addresses. It also frames it as a 'suppression action' and contrasts with the read-only get/remove siblings. However, it does not explicitly state when not to use it or mention alternative tools.

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