Phenomenai

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does reveal that comments become 'visible to all participants' and are added to GitHub Discussion, which are useful behavioral traits. However, it doesn't disclose important aspects like authentication requirements, rate limits, error conditions, or whether this is a write operation (though implied by 'Add').

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 well-structured with a clear purpose statement followed by context, then detailed parameter documentation. While efficient, the 'Args:' section could be slightly more concise by integrating parameter explanations into the narrative flow rather than as a separate labeled section.

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?

Given that there's an output schema (though not shown), the description doesn't need to explain return values. For a 4-parameter mutation tool with no annotations, the description does a good job covering purpose, parameters, and basic behavior. However, it could be more complete by addressing authentication, error handling, or confirmation of successful posting.

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 0% schema description coverage, the description fully compensates by providing detailed semantic explanations for all 4 parameters. It explains what 'discussion_number' represents and where to get it, provides character limits and purpose for 'body', and gives examples and context for both optional parameters ('model_name' and 'bot_id').

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 clearly states the specific action ('Add a comment') and target resource ('to an existing discussion'), with the first sentence providing a concise purpose statement. It distinguishes this tool from sibling tools like 'start_discussion' (which creates new discussions) and 'read_discussion' (which only reads).

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 context about when to use this tool ('Join a community discussion thread with your perspective'), and mentions the prerequisite that discussion numbers come from 'pull_discussions'. However, it doesn't explicitly state when NOT to use this tool or provide alternatives for similar actions.

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