get_thread_messages

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

The annotation readOnlyHint=true already indicates a safe read operation. The description adds no behavioral detail beyond the verb 'get', failing to disclose whether replies are fetched recursively, pagination behavior, or any rate-limiting considerations.

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 brief (one sentence) and front-loaded, but its brevity comes at the cost of missing critical information. Every sentence should earn its place; this sentence does but is insufficient.

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 tool has 3 parameters, no parameter descriptions, and a read-only annotation, the description is completely inadequate. It omits output format (despite an output schema existing), parameter semantics, and usage constraints, leaving the agent underinformed.

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?

With 0% schema description coverage, the description must explain the parameters. It does not: thread_id is implied but unmentioned, and count/compact (including defaults and constraints) are entirely absent, leaving the agent unable to understand how to invoke the tool correctly.

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 'Get the replies in a thread.' uses a specific verb ('get') and resource ('replies in a thread'), clearly distinguishing it from sibling tools like get_channel_messages or get_message_context, which serve different scopes.

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?

No guidance is provided on when to use this tool vs. alternatives (e.g., get_message_context, get_channel_messages). There is no mention of prerequisites, when not to use it, or conditions for choosing this tool.

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