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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is partly covered. The description goes beyond them by stating the concrete consequences: unfinished work is interrupted, partial changes may remain, completed changes are NOT rolled back, and the session itself is retained. That 'what survives and what persists' detail is exactly the context an agent needs before calling a destructive tool.

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, no filler, with the core action front-loaded and the consequences following immediately. Every clause carries information.

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 single-parameter cancellation tool with no output schema, the description covers the action, its side effects, and session persistence reasonably well. It omits what the caller receives back and whether a subsequent call to another tool is needed to resume or clean up.

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 0% and the description never mentions sessionId. The schema constrains the value to a UUID and names it, so the intent is inferable from the tool purpose, but the description does not compensate for the coverage gap by explaining which session to target (e.g., the active vs. any historical session).

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+resource: 'Cancel the in-progress turn of a Replo session.' An agent can distinguish this from the read-oriented get_agent_session and the interaction-oriented resolve_agent_interaction without opening a schema. It stops short of explicitly naming a sibling for contrast.

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 implied by 'in-progress turn' — the tool is for interrupting a running turn — but there is no explicit when-to-use statement, no exclusions, and no pointer to alternatives such as resolve_agent_interaction for sessions waiting on input. The agent must infer the trigger condition.

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