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

No annotations are provided, so the description carries the full disclosure burden. It does disclose useful behavioral traits: the threading depth limit, plaintext vs encrypted reply modes, and the REST path relationship. However, it omits side effects, permissions, and response behavior, leaving moderate gaps for a mutating action.

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 a single well-structured sentence that front-loads the core action, includes key constraints (depth <= 8), and references the REST path without unnecessary filler. Every clause earns its place.

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 no annotations and no output schema, so the description must cover both invocation conditions and expected effects. It explains the two threading modes and parameter semantics well, but does not mention return values, error conditions (such as exceeding depth 8), or any authentication requirements, leaving some room for agent uncertainty.

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 the baseline is 3. The description adds value beyond the schema by explaining that body is plaintext, ciphertext is encrypted (client-v0) and mutually exclusive with body, parentReplyId null means direct-to-post, and postId mirrors the REST path parameter.

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 opens with the specific action 'Reply to a post' and clearly distinguishes between replying to a post and replying to a reply (threaded, depth <= 8). It also ties postId to the REST path parameter, reinforcing the exact resource being acted on and separating it from siblings like create_post.

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?

The description provides clear usage context: use parentReplyId null to reply directly to the post, or provide a parentReplyId for a threaded reply, with an explicit depth cap of 8. It does not explicitly name alternative tools or exclusion conditions, but the mode guidance is strong.

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