Get Inbox Agent

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

Annotations already declare this a safe read (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description still adds real behavioral context: the never-configured case returns empty settings, and it enumerates the four valid tone presets, which is valuable given no output schema exists.

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 sentences, front-loaded with the core action, then the edge case, then the enum values. No filler; every sentence carries information an agent would otherwise lack.

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?

There is no output schema, so the description correctly compensates by naming the returned fields and the tone preset values. It is nearly complete for a single-parameter getter; only a brief note on the shape of "actions" would round it out.

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% and the single inboxId parameter is fully documented there (including the email-address alternative and the note that it is not the receiving address). The description adds nothing about the parameter, so the baseline 3 applies.

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 and resource ("Get the AI agent settings of a Resend inbox") and then enumerates exactly what those settings consist of: instructions, tone, and allowed actions. The get/update verb contrast with the sibling update-inbox-agent is unambiguous, so an agent can select it without opening the 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?

Usage is only implied: the tool reads agent configuration and the sibling update-inbox-agent mutates it, but the description never states that routing explicitly. It does surface one useful condition — an unconfigured inbox returns empty settings — but offers no exclusions or prerequisites beyond that.

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