download_story

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

With no annotations provided, the description takes on full responsibility for behavioral transparency. It discloses the output format (MP4/JPG URLs), the 24-hour visibility window, and the HTTP 422 error for private accounts. It lacks details on rate limits or authentication but is adequate for a read-only retrieval 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 description is extremely concise, using two sentences to convey the entire purpose, constraints, output, and error condition. Every sentence adds informational value without 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?

Given the tool's simplicity (one parameter, straightforward operation, no output schema required), the description is fully complete. It covers purpose, input constraints, output specs, and error handling, leaving no gaps.

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?

The schema covers one parameter (username) with 100% description coverage. The description adds value by clarifying that the leading @ is optional and emphasizing the username must be public, which enhances the schema's definition.

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 tool fetches active Instagram Stories for a public username, specifies the 24-hour window, and distinguishes it from siblings like download_reels by focusing specifically on Stories.

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 on when to use (for public usernames) and the error condition for private accounts. Although it doesn't explicitly state when not to use, the sibling tools cover different use cases, making the guidance sufficient.

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