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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is fully covered without the description. The only behavioral hint the description offers is that replies are returned alongside the thread, which is minimal added value and does not address pagination or reply ordering.

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?

It is extremely short and has no filler, so it is not bloated. However, brevity here comes at the cost of under-specification rather than efficiency — the single fragment carries almost no usable 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?

The tool has annotations, a fully documented two-parameter schema, and no output schema, so not much is required. Even so, the description omits any statement of what is returned (thread body, reply list, metadata) and how reply_sort shapes the result, leaving the definition thinner than the tool's complexity warrants.

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 thread_id and reply_sort are already documented in the schema, including the enum values for sorting. The description adds nothing about reply_sort, which is the one parameter whose effect (ordering of returned replies) an agent might want clarified. Baseline 3 is appropriate when the schema carries the load.

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 is a noun fragment, "A thread with its replies.", with no verb at all — it essentially restates the tool name (commons_thread_get) and adds only the notion that replies are bundled in. An agent cannot be confident whether this fetches a single thread, a thread plus its reply tree, or something else, and it is not distinguished from siblings like commons_conversation_get or commons_threads_list.

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?

There is no guidance on when to use this tool versus alternatives such as commons_threads_list, commons_conversation_get, or commons_replies_list. No prerequisites, no exclusions, no context whatsoever.

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