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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered without the description. The description contributes only the mild scoping detail that the lookup is bound to one inbox account, adding little beyond the structured fields.

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?

A single short sentence with the verb and resource front-loaded, leaving no filler or redundancy to trim.

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 read-only lookup with annotations covering the safety profile and no output schema, the essentials of identifying the lookup target are present. It still omits what a rule record contains, error behavior for an unknown ID, and how the two account-scoping parameters interact.

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 carry the burden for three parameters. It partially does so: 'by ID' corresponds to the required id, and 'for one inbox account' gestures at the emailAddress/emailAccountId scoping pair, but it never explains how those two account parameters relate or which is authoritative.

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?

States a specific verb (get) and resource (automation rule) with singular scope, which implicitly separates it from list_rules and the create/update/delete_rule siblings. It never names those siblings explicitly, so the differentiation is inferable rather than stated.

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 phrase 'by ID' implies the precondition that you already hold an identifier, which is a usable usage cue. However, there is no explicit guidance on when to reach for get_rule versus list_rules or search, and no exclusions or prerequisites.

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