list_channels

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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds behavioral depth by explaining that 'limit' is an upper bound on the raw fetch before filtering, and 'compact' reduces payload size by ~5x. This goes beyond the annotation flags and gives the agent useful implementation details.

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 compact and well-structured using a bulleted list. The first line immediately states the core purpose and exclusion. Each parameter gets a brief, clearly formatted explanation. No superfluous words or redundant information.

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 7 optional parameters and the existence of an output schema, the description covers all necessary aspects: what type of items are returned, how filtering works, and performance-related options. It fully compensates for the lack of schema descriptions and leaves no major gaps in understanding the tool's behavior.

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?

The input schema has 0% description coverage, so the description carries the full burden. It thoroughly explains every parameter: archived enum semantics, limit as a raw-fetch bound, only_unread filtering, is_pinned options, min/max participants as subscriber filters, and compact payload behavior. This adds meaningful context that the schema alone lacks.

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 clearly identifies the tool as listing broadcast channels only, explicitly excluding supergroups. This distinguishes it from sibling tools like list_chats, list_groups, and list_pm_users. The verb 'list' and resource 'channels' are specific and 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?

The description states that this tool handles only broadcast channels (no supergroups), which gives clear context for when to use it over alternatives. It does not explicitly name alternative tools or state exclusions, but the scoping is implied strongly. The parameter descriptions also clarify how to control the results, e.g., archived, only_unread, and participant count filters.

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