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

Annotations include readOnlyHint=false, destructiveHint=true, idempotentHint=true. The description adds valuable behavioral context beyond these: 'Effect: external-email' indicates real-world side effects, 'Retry after reading the current resource state' suggests concurrency considerations, and permissions are explicitly listed. It does not contradict annotations.

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?

The description is four compact sentences, front-loaded with the primary action, then providing effect, retry guidance, permissions, and an API link. Every sentence adds information without 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?

Given the output schema exists and the tool is simple (2 parameters, one nested with an enum), the description covers purpose, usage context, behavioral effects, permissions, and retry guidance. It lacks explicit error scenarios or return value details, but those are partially covered by the output schema and the retry hint.

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%, so baseline is 3. The description adds minimal parameter-level detail—it implies that the body status field controls start/pause, but does not describe parameters beyond what the schema already provides. The body description in schema is generic ('exact JSON request body'), and the nested enum is self-explanatory.

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 uses a specific verb phrase 'Starts or pauses' with a clear resource 'one Sequence', and explicitly states it does not change content or delivery settings, which distinguishes it from sibling tools like sequences_update. This is 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?

It provides clear context: 'without changing its content or delivery settings' implies it is for status-only changes, and 'Retry after reading the current resource state' is a specific usage instruction. However, it does not explicitly name alternative tools or provide a when-not-to-use exclusion beyond the implied scope.

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