fetch_thread

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It discloses that the tool fetches the post and its top comments, and implies a read-only operation. It does not mention return format or potential limits (e.g., max_comments), but the schema covers the limit and the description provides the core behavior.

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, front-loaded sentence that immediately states the action and purpose. Every word contributes value; there is no redundancy or filler.

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 the tool's simplicity (2 parameters, 1 required) and lack of output schema, the description plus schema provide sufficient context. It covers what the tool does and when to use it. It does not detail the exact response structure, but for a read-only fetch with clear parameters, that is acceptable.

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 schema already describes 'url' and 'max_comments' (including default and range). The description adds minimal semantic value beyond reinforcing that 'top comments' are included, but it does not clarify parameter syntax or edge cases beyond schema.

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 verb ('Fetch'), the resource ('a Reddit post with its top comments'), and the use case ('before drafting a reply'). It is easily distinguished from sibling tools 'search_reddit' and 'score_leads' since it retrieves a specific known thread rather than searching or scoring.

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 gives explicit context for when to use the tool: 'before drafting a reply' (i.e., when you need the full conversation for a known post). It does not explicitly list exclusions or mention alternatives, but the sibling context makes the intended usage clear.

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