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

Annotations already cover the safety profile (readOnlyHint=true). The description adds the underlying Platform API endpoint (GET /group_channels) and the return envelope { channels[], next }, which tells the agent pagination is token-driven. It does not discuss rate limits or auth, but that is a minor gap given annotation coverage.

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, front-loaded with purpose, then filters, then endpoint and return shape. No filler and nothing buried.

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?

With no output schema, the description usefully declares the return shape and pagination token. Combined with full schema coverage and a readOnly annotation, an agent has enough to call it correctly; only ordering/pagination conventions are left implicit.

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 the schema already explains all 11 parameters, including defaults and enums. The description's parenthetical filter summary (name, members, distinct/public/super) largely restates what the schema documents, 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?

States a specific verb and resource ("List group channels in the application") plus the filtering axes (name, members, distinct/public/super mode). It does not explicitly differentiate from the close sibling sendbird_list_group_channels_by_user, but the scope is otherwise 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?

Usage is implied by the resource and filter summary, but there is no explicit when-to-use guidance and no named alternative (e.g., list_group_channels_by_user, list_open_channels). An agent must infer the choice from the sibling names alone.

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