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

Annotations declare a non-read-only, non-destructive, closed-world call, and the description adds meaningful context beyond that: the output is two artifacts (link plus short resume code) bound to the current session. It does not mention expiry, reuse limits, or whether the link is single-use, which would matter for a generated credential.

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?

Two sentences, zero filler. The usage condition leads and the return contract follows, which is the right front-loading for a one-parameter tool.

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 correctly carries the return-value burden by naming both returned artifacts. It leaves out link lifetime and what happens to the session after resuming elsewhere, minor gaps for a tool this simple.

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% and the single 'session' parameter is fully documented there, including the cxs_ prefix hint. The description's 'for this session' reinforces the scoping but adds no new mechanics, so the baseline of 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 outcome: it returns a resume link and a short resume code tied to this session. The verb is implied rather than stated, and it doesn't explicitly contrast with siblings like open_journey or get_journey_progress, but the return artifact makes the tool's identity unambiguous.

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 a clear trigger condition: 'when the user wants to continue the journey later, on the website or in another assistant.' That is a strong situational cue. It stops short of naming an alternative or an exclusion case, so it doesn't reach the explicit when/when-not bar.

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