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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses important traits: the cursor is durable, acknowledgements are monotonic, and retries are safe. It does not detail error handling or return behavior, but the core mutation semantics are transparent.

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, all informative and front-loaded: operation, parameter guidance, and retry semantics. No filler or redundancy.

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 one-parameter tool with no output schema, the description covers the action, precondition, parameter source, and safety semantics. A minor gap is that it does not hint at what response or confirmation the caller should expect after acknowledging.

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 input schema fully documents the single 'cursor' parameter, including its type, minimum, and origin. The description reinforces this by saying 'Pass that response's cursor,' but adds little meaning beyond the schema's existing description.

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?

The description states a specific action ('Advance your durable change cursor') and identifies the exact resource and precondition ('after you have processed a complete what_changed_since response'). It clearly distinguishes itself from the sibling what_changed_since as the acknowledgement counterpart.

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?

The description provides clear when-to-use guidance: only after fully processing a what_changed_since response. It also notes that retries are safe, which helps an agent decide to reuse it safely, though it does not explicitly enumerate exclusions or alternative tools.

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