channels

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

With no annotations provided, the description must carry the full behavioral burden. It does disclose the return shape (a Dict with a channels list containing id, server_id, server_name, name, last_message_id) and implies a read-only list operation. However, it omits auth requirements, rate limits, pagination, and whether results are cached or live, leaving clear gaps for an unannotated tool.

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 front-loaded with its purpose, then uses compact Args and Returns sections. Every line serves a purpose: the parameter explanation and return shape are useful given the absent output schema. There is no redundant or filler text.

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?

There is no output schema, but the description compensates by documenting the return dictionary structure. For a simple one-parameter list tool with no annotations, the description covers purpose, parameter semantics, and return shape. It still lacks operational details like auth, rate limits, or pagination, keeping it from a top score.

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 coverage is 0%, so the description must define the only parameter. It does so adequately: 'server: optional server ID or name to restrict to' explains that the parameter is optional, accepts an ID or name, and filters the result. It could add format examples or default behavior, but it compensates well for the missing schema description.

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 opens with 'List channels known to the archive', giving a specific verb (List) and resource (channels). It also scopes the result with the optional server filter, so an agent can understand the operation without reading the schema. However, it does not explicitly differentiate this tool from sibling tools like servers or search, so it falls short of a 5.

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 only explains the optional server parameter; it offers no guidance on when to choose channels over siblings such as servers, recent, or search. There are no prerequisites, exclusions, or alternatives mentioned, so an agent receives minimal routing help. This matches the rubric's 'no guidance' level.

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