Get Sending Connection

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds real value on top: the required email.send scope is an auth requirement not present in structured fields, and the explicit non-goals prevent the agent from assuming credit or provider-readiness checks. It says nothing about live-call cost, latency, or the conditional-request behavior, but the essential behavioral profile is covered.

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 short sentences, front-loaded with the action, then the permission requirement, then the exclusions. Every sentence carries distinct information with no repetition of the name or title.

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?

An output schema exists, so return values need no prose, and the description still previews the payload (team, label, permissions). With zero required parameters and one documented optional header, nothing an agent needs in order to call this correctly is missing.

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 optional If-None-Match parameter is fully documented in the schema itself, so the description owes nothing there. It adds no additional parameter meaning, which is the baseline 3 case when the schema does the work.

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?

Names a specific verb pair (validate/read) and a specific resource (the Sending credential plus its team, connection label, and permissions), so the agent knows exactly what comes back. The closing negation separates it from sending_send_email and other siblings that might be confused with it.

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?

States a concrete prerequisite (requires email.send) and explicit exclusions: it does not send email, check credits, or check provider readiness. It stops short of naming the sibling tool to use for those purposes, so the agent must still infer the alternative, which keeps it out of the 5 tier.

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