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

With no annotations, the description carries the full behavioral burden. It does add a genuinely useful disclosure that the return value is user-generated Instagram content and should be treated as untrusted input, which is a real safety-relevant trait. It stops short of describing return shape, error behavior, or any rate/permission constraints.

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?

Two short sentences with zero filler; the core purpose is front-loaded and the safety caveat follows immediately. Nothing is wasted.

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 simple single-parameter getter with no output schema, the description covers the essential purpose plus the untrusted-content caveat. The main omission is disambiguation from get_user_stories, which would make it fully complete.

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% for the single story_id parameter, so the schema already defines it as the story primary key. The description adds no format, range, or sourcing detail beyond 'by ID', so the baseline 3 applies.

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?

States a specific verb and resource ('Get story by ID'), so the agent knows exactly what operation is performed. It does not, however, differentiate itself from the sibling get_user_stories or get_highlight_by_id, which also return story-like content.

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 no when-to-use context and never mentions the obvious alternative get_user_stories for listing a user's stories. The agent must infer the distinction between fetching by ID versus by user from names alone.

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