get_mail_rule

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

Annotations declare readOnlyHint=true, and the description's 'Get' is consistent with that, so there is no contradiction. However, the description adds only minimal behavior beyond the annotation: it clarifies the operation returns a single rule by ID. It does not disclose error behavior, return format, or auth requirements, but for a simple read-only getter this is a minimum viable level.

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 a single, front-loaded sentence: 'Get one mail rule by ID.' Every word earns its place, with no filler or repeated schema information.

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 simplicity—one required parameter, read-only annotation, and no output schema—the description is mostly adequate for an agent to call it. The main gap is the absence of explicit return-value or not-found behavior, but for a straightforward get-by-ID operation the missing details are relatively minor.

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 0%, so the description must compensate for the undocumented id parameter. The phrase 'by ID' reinforces that the id parameter identifies the mail rule, but it adds little beyond the parameter name and type already present in the schema; it does not explain where the ID comes from or how to find valid IDs.

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 a specific verb and resource: 'Get one mail rule by ID.' It clearly differentiates this from siblings like list_mail_rules (plural listing) and create/update/delete_mail_rule by specifying a single item fetched by identifier.

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?

No guidance is given about when to use this tool versus alternatives. It does not mention that list_mail_rules should be used to enumerate rules first, nor does it state exclusions or conditions. The 'by ID' requirement is implied but no explicit usage context or prerequisite is provided.

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