Refresh registration

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

Adds real behavior beyond the annotations: it writes only when the registration has actually drifted, and it returns the session id it now holds plus the one it replaced. That is fully consistent with idempotentHint=true and destructiveHint=false, and it supplies return-value behavior that no output schema covers.

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 action, then the trigger, then the return value. The middle clause ('that claim is the symptom of a stale registration, not a fact about your tools') is long but earns its place because it prevents a wrong conclusion.

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 zero-parameter, non-destructive refresh tool with no output schema, the description covers the trigger, side effect, safety, and return shape. There is nothing an agent needs in order to invoke it correctly that 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?

The tool takes zero parameters, so per the baseline this scores 4. The description correctly implies no input is needed by anchoring everything to 'this session,' with no misleading parameter hints.

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: 'Re-publish this session's Tin Can registration.' It also gives the observable effect ('so peers can see it can reply'), which distinguishes it from siblings like send_peer or peers that also touch peer visibility.

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 explicit triggers (a peer reports the session unreachable, or an arriving message claims no send_peer) and explicitly notes Tin Can normally does this automatically, so the agent knows this is the exception path. It even pre-empts a false inference by framing the 'no send_peer' claim as a registration symptom.

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