Get Inbox Agent

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 covered. The description adds useful behavior beyond that: an unconfigured inbox returns empty settings (no instructions, tone, or enabled actions), which is a distinct and valuable edge case.

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?

Three tight sentences, front-loaded with the purpose, followed by the edge-case behavior and the parameter sourcing. Every sentence carries information; no 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?

With no output schema, the description carries the burden of explaining return values, and it does: instructions, tone, and allowed actions, plus the empty-settings case. Combined with the ID-sourcing note, an agent has everything needed to call it 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 coverage is 100% for the single inboxId parameter, so the schema baseline is 3. The description goes further by clarifying the parameter is an inbox ID and not an email address, plus where to obtain it, adding real disambiguation value.

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+resource ('Get the AI agent settings of a Resend inbox') and enumerates the returned facets: instructions, tone, and permitted actions. An agent can distinguish this from siblings like get-inbox or list-inboxes without opening any schema.

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?

Gives clear context by stating it takes an inbox ID (not an email address) and points to list-inboxes/get-inbox as the ID source. It does not explicitly contrast with the sibling update-inbox-agent (read vs. mutate), so the when-not guidance is implied rather than stated.

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