list_thread_replies

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

No annotations are provided, so the description carries the full burden and does so well: it discloses ordering ('newest first'), the inclusion of the parent message, the hard cap on replies, system-message exclusion, and — critically — a silent truncation behavior where the oldest replies are dropped with no marker. That silent-data-loss disclosure is exactly the kind of trait an agent cannot learn from the schema.

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?

Four short sentences, each earning its place: purpose first, then prerequisite, then return shape, then the truncation caveat. No filler and no restatement of the tool name.

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 return values need not be spelled out, yet the description still conveys the useful structure (parent first, then replies) and the truncation edge case. It stops short of telling the agent how to recover the omitted oldest replies or what permissions the call requires, which are the only meaningful remaining gaps.

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 0%, so the description must compensate; it clarifies that message_id must be a top-level parent message (retrieved via list_channel_messages) and gives the valid limit range (1-200) plus its default. team_id and channel_id are left to their self-evident names, which is a minor but real gap at zero coverage.

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 replies in a channel message thread') and explicitly scopes to threads versus the general channel message listing handled by list_channel_messages. An agent can distinguish it from every sibling that deals with messages without opening a schema.

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?

Names the prerequisite and the alternative path directly: 'Use list_channel_messages to get the parent message_id (a top-level message).' The condition that selects this tool (you have a parent message and want its replies) is made explicit rather than inferred.

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