reply

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

Annotations already indicate non-read-only and non-destructive behavior. The description adds specific behavioral context: notification defaults (everyone who interacted) and how to override them. This is useful beyond the annotations, though it could explicitly mention that this action sends notifications.

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 and then efficiently adds the key notification context. No filler or unnecessary repetition.

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 the main behavioral aspects (action, target types, notification defaults) and together with the input schema and output schema provides sufficient information for correct invocation. It does not mention error conditions or prerequisites (e.g., membership in the conversation), but these are reasonable gaps given the presence of an output schema and the tool's relative simplicity.

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 parameters are well-documented. The description adds value by clarifying the default notification behavior for thread replies and the conditional nature of recipients/groups/notifyAudience. While some redundancy exists, the description's nuance (especially the default) helps the agent understand parameter interactions.

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 action ('post a reply') and resource ('thread or conversation'), specifying that thread replies become comments and conversation replies become messages. This distinguishes it from sibling tools like create-thread (different resource) and react (different 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?

The description explains when to use optional parameters (groups, recipients, notifyAudience) and the default notification behavior. However, it does not provide explicit guidance on when not to use this tool (e.g., when to use 'react' or 'mark-done' instead), leaving selection somewhat implicit.

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