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

With no annotations, the description carries the full burden. It discloses the flat response structure with parent_id, explains cursor pagination for threading, and specifies input formats per platform. It does not mention side effects, but as a read operation this is implicit. It provides solid behavioral insight beyond the bare schema.

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 dense but every sentence adds essential value. It opens with the core behavior and response structure, then cursor mechanics, then platform-specific formats. No fluff or repetition; it is appropriately sized for the complexity.

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?

Despite lacking an output schema, the description covers all necessary aspects: response format (flat with parent_id), pagination (cursor), and parameter semantics for every platform. It is comprehensive for an agent to call the tool correctly without additional documentation.

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 0%, so the description must fully compensate. It does this extensively: it defines valid formats for the 'id' parameter on every supported platform (e.g., shortcode, /p/ URL, t3_ id, secUid, etc.), explains 'cursor' usage for replies, and implicitly defines 'platform' by listing platforms. This is far beyond what the schema offers.

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 title and opening sentence state the tool's purpose precisely: 'Get comments on a post' and 'Comments on a post, flat, with parent_id set on replies...' This clearly distinguishes it from siblings like get_post or get_user_posts. The description also explains the comment structure, making the purpose unambiguous.

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 clearly indicates the tool is for retrieving comments on a post, giving strong context. It does not explicitly compare with alternatives or state when not to use it, but the context is clear enough for an agent to select it when comments are needed. Slight deduction for lack of explicit exclusions.

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