fetch_post_replies

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

With no annotations, the description carries the behavioral burden, and it does so well. It discloses the read-only nature ('Fetch'), sorting behavior, pagination cursor semantics, default limit, and the exact shape of the response. It does not cover rate limits or error conditions, but those are not essential for a straightforward fetch tool.

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 summary sentence is front-loaded and the Args/Returns sections are compact and relevant. Every line contributes useful information without fluff or redundancy.

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 four-parameter read operation with no annotations, the description is complete enough to call the tool correctly. It covers all required inputs, optional behaviors, and the returned data structure. The existence of an output schema further reduces the burden on the description.

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 defines every parameter: media_id is the unique post ID, reverse_sort controls ordering, limit caps replies, and after is the pagination cursor. This adds meaningful semantics beyond property names and defaults.

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 opens with a specific verb and resource: 'Fetch replies and comments attached to a specific Threads post.' This clearly distinguishes the tool from siblings like get_post_details, list_recent_posts, and get_post_analytics, which target different data.

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?

Usage is implied through the description: an agent can infer this tool is for retrieving replies to a specific post. However, there is no explicit guidance on when to prefer it over alternatives, no exclusions, and no mention of related sibling tools.

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