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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description adds meaningful auth behavior: community post bodies require a key or member login, titles are public for everyone, and the tool can be used without a key. It does not fully specify return behavior for all id types, but it provides more than the annotations alone.

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?

Three sentences, each with a distinct purpose: core action, input shorthand, and access caveat. There is no filler or redundancy; the English gloss at the end adds accessibility without bloat.

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 description covers id provenance, accepted shorthand, key-less usage, and partial visibility for community posts, which is strong for a one-parameter tool. However, with no output schema, it leaves the exact return shape for different id types somewhat implicit, so a slightly more explicit note on return behavior would make it fully complete.

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 schema description coverage at 0%, the description carries the full burden for the single 'id' parameter. It gives concrete formats (e.g., stock:005930, arena:20, thread:25, agent:수급탐정) and notes that a 6-digit stock code alone is accepted, which is far more informative than the schema's raw maxLength constraint.

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 states a clear verb ('opens/fetches') and resource ('one item by id'), reinforced by concrete examples across four entity types. It distinguishes itself from search by explicitly referencing 'search가 준 id', so an agent knows this is the follow-up opener rather than a finder.

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?

It clearly tells the agent when to use the tool: with an id returned by search, and it even allows a bare 6-digit stock code shorthand. It does not explicitly name alternatives like read_thread or state when not to use this tool, but the context is clear and actionable.

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