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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety and repeat-call profile is covered structurally. The description adds a useful eligibility constraint (only 'Running' runs), but says nothing about side effects on the run itself (terminated vs. rolled back), partial results, or any permission requirements beyond the status check.

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, each earning its place: the action, the upstream call, and the precondition. The core action is front-loaded and nothing is repeated from the schema or annotations.

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 destructive, idempotent mutation with only three well-documented parameters and no output schema, the description supplies the key operational context (prerequisite tool, eligibility rule). It is nearly complete, though it omits any note on the effect on the run or error behavior when the status precondition fails.

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 all three parameters carry descriptions, so the schema does the heavy lifting; baseline 3 applies. The description merely echoes that runName comes from get_live_flow_runs, which the schema already states, and adds no format, casing, or identifier details for environmentName/flowName.

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 names a specific verb and resource ('Cancel a currently running Power Automate flow run') plus the scope qualifier 'via the live PA API', making it clearly distinct from siblings like resubmit_live_flow_run, trigger_live_flow, and set_live_flow_state. An agent can identify exactly what the tool operates on without opening the schema.

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?

It gives an explicit prerequisite and sequencing rule ('Use after get_live_flow_runs to obtain the run name') and a precondition ('Only runs with status "Running" can be cancelled'), which tells the agent both when to call it and when it will fail. It stops short of naming a fallback when the precondition is unmet (e.g., what to do with non-Running runs), so it is a strong 4 rather than a 5.

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