add_address_rule

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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals that block rules are enforced on both send and receive, which adds meaningful insight beyond the schema. However, it does not clarify behavior for allow rules, idempotency, error handling, or permissions, leaving gaps for a mutation tool.

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 two sentences, front-loaded with the action and resource, and includes a key behavioral detail. There is no redundancy or filler.

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?

For a simple three-parameter tool with no output schema, the description covers the core purpose and an important behavioral trait. However, it leaves ambiguity about the 'both' direction default and whether block rules are always both, potentially confusing agents. More details about idempotency or duplicate handling would make it complete.

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 67% (pattern and direction have descriptions, kind does not). The description reinforces the pattern format and kind values ('allow' or 'block'), but adds little beyond the schema. The behavioral note about block rules does not directly clarify parameter semantics. Overall, the description contributes marginal value over 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 action ('Add') and the resource (an allow or block rule for an email address or bare domain). It distinguishes from siblings like list_address_rules and delete_address_rule by specifying the creation operation and the rule types.

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 implies when to use the tool: when you need to add allow/block rules. It provides behavioral context (block rules enforced on both send and receive) but does not explicitly contrast with alternatives or mention exclusions such as 'use list_address_rules to check existing rules.' Guidance is implied rather than explicit.

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