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

No annotations are supplied, so the description carries the whole behavioral burden for a mutation tool. It discloses the auth requirement, which is real value, but says nothing about whether the comment is immediately public, whether it can be edited or removed, rate limits, or what a success response contains — despite the notification_message parameter hinting at a follow-up failure path that is left unexplained.

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?

Two short sentences with zero filler, and the core action is front-loaded before the threading detail and the login prerequisite.

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?

For a mutation tool with no annotations and no output schema, the description should say what happens on success and how the notification_message failure path works. It covers the action and the auth prerequisite but leaves the outcome and error behavior for an agent to guess.

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 coverage is 100%, so all three parameters are already documented in the schema, and the description's note that parent_id is 'the story or comment id' merely restates the schema. Baseline 3 applies since the schema does the heavy lifting.

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?

States a specific verb and resource — 'Post a comment' — and clarifies it works on both stories and reply threads. This clearly separates it from sibling write tools like submit_story and upvote, though the description never names those siblings explicitly.

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 only guidance is the prerequisite 'Requires login session', which is useful but is a precondition rather than a when-to-use rule. There is no statement of when to prefer this over other tools, and no exclusions or failure conditions an agent should anticipate.

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