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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, covering the safety profile. The description adds nothing beyond that — no note on pagination defaults, ordering, or whether the list is filtered by any channel state — so it does not go past the structured fields.

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?

A single short sentence that is front-loaded and free of filler. It is appropriately sized for a simple list tool, though the brevity edges toward under-specification rather than true concision.

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?

The output schema and annotations carry much of the burden, and the parameters are fully documented in the schema, so the tool is callable. Still, for a channel-scoped list tool the description omits any note about pagination behavior or how the result relates to the channel viewer tools, leaving the picture only minimally complete.

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%, with the paging parameters and workspace ID each documented in the schema, so the baseline of 3 applies. The description adds no extra meaning about paging semantics or workspace scoping.

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 (List) and resource (channel subscribers), so the basic operation is unambiguous. However, it gives no differentiation from siblings that operate on the same channel audience, such as invite_channel_viewers and remove_channel_viewers, nor does it clarify whether 'subscribers' and 'viewers' are the same population.

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?

There is no statement of when to use this tool versus alternatives, no prerequisites, and no exclusions. The agent must infer everything from context.

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