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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety is covered. The description goes further by explaining the delivery semantics (a delivery reaches every active device of each assigned user plus individually assigned devices), which is genuine behavioral context beyond the annotations. It does not mention auth requirements or rate limits, but for a read tool that is acceptable.

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?

Front-loaded with the core action, then usage guidance, then return shape. Three sentences and every one carries weight; the delivery-semantics sentence is the most verbose but still informative rather than filler.

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?

An output schema exists, so the description's return-value narration is technically redundant, yet nothing an agent needs is missing: purpose, when-to-use relative to the set_channel_* siblings, and the resource relationships are all covered.

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 the schema already documents slug and public_id including the 'provide one, or both must match' rule. The description adds no syntax or format detail for the parameters beyond what the schema provides, so baseline 3 applies.

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?

Specific verb (Get) plus resource (one channel) and explicit scope (with the users and individual devices assigned to it). It is easily distinguished from list_channels (plural, all channels) and the set_channel_* mutators named in the text.

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?

Explicitly states when to call it: 'Call this before set_channel_users or set_channel_devices, which replace the whole list, so you can keep existing assignments.' It names the alternatives and the condition that selects this tool over them, leaving nothing to inference.

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