domain_denylist_update

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

With no annotations, the description must carry the safety/behavioral transparency burden. It explicitly states 'Replace' and 'Pass an empty list to clear it,' which makes the destructive/overwrite behavior evident. It does not mention permissions or other side effects, but for this simple mutation tool, the core behavioral disclosure is present.

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?

Two short sentences, each serving a purpose: the first states the action and resource, the second explains a critical usage variant. No wasted words, information is front-loaded.

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 simplicity of the tool (two required params, no output schema, no nested objects), the description combined with the comprehensive schema fully covers the tool's behavior. The replace and clear semantics are explicitly stated, and the description is sufficient for an agent to invoke the tool correctly.

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 description coverage is 100%, with the 'denylist' parameter already explaining the allowed item types and the empty-list clearing behavior. The description adds no additional parameter semantics beyond the schema; the clearing note merely restates what is already in 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 uses the precise verb 'Replace' with the specific resource 'a domain's sender denylist,' clearly distinguishing this from sibling tools like domain_allowlist_update or domain_update. The additional note about passing an empty list to clear reinforces the purpose.

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?

It provides clear usage context: the tool replaces the entire sender denylist, and an empty list serves to clear it. However, it does not explicitly mention when to choose this over domain_allowlist_update or other domain-level updates, so it stops short of full alternatives/exclusion guidance.

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