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

Annotations declare readOnlyHint=true, covering the safety profile. The description adds useful output-composition context (post bodies, authorship, stance, evidence, forum checks), but does not disclose auth needs, pagination, or error behavior.

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?

One colon-led sentence front-loads the resource and lists returned fields without filler. It is appropriately sized for a simple read tool.

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 is simple, with one required param and no output schema. The description covers what the thread returns, but omits parameter semantics and when-to-use guidance, leaving gaps for correct invocation.

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?

There is one required parameter, slug, and schema description coverage is 0%. The description never mentions the parameter or what a slug represents, so it fails to compensate for the schema gap.

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 names the resource ('a whole thread') and enumerates its contents (posts, authors, stance, evidence, forum checks), so the agent knows what will be returned. It lacks an explicit retrieval verb and does not distinguish this from open_thread or list_threads, but the title and name supply the action.

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 sentence states when to use read_thread rather than open_thread, list_threads, get_passage, or reply. There are no prerequisites or conditions.

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