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

With no annotations the description carries the full burden, and it does add real behavioral value: it discloses the return shape ('profile objects with recent posts') and a cost model ('$0.01 per profile scraped'), which an agent needs in order to budget calls. It omits rate limits, runtime/latency expectations, and failure modes, so it is not complete for a scraper with zero structured safety hints.

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?

Three sentences, each earning its place: what it scrapes, when to use it, and what it returns plus cost. The purpose and scope are front-loaded and there is no filler or repetition.

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?

There is no output schema and no annotations, so the description must carry more weight, and it does cover purpose, use cases, returned shape and pricing. It leaves gaps around rate limiting, pagination or result limits, and error behavior for a network-scraping tool, but nothing essential to invoking the single required parameter is missing.

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% and there is only one parameter, so the schema already explains the profiles list and its format. The description adds no format detail and actually introduces a 'hashtag posts' capability the parameter does not expose, which slightly muddies rather than clarifies parameter meaning. Baseline 3 is appropriate.

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 gives a specific verb and resource ('Scrape Instagram profiles and hashtag posts') plus the concrete fields returned ('followers, posts, engagement metrics'), and the Instagram scope implicitly separates it from tiktok_scraper, youtube_scraper and linkedin_profile_scraper. It falls short of 5 because the 'hashtag posts' claim is not backed by the input schema, which only accepts a profiles array, leaving the agent unsure whether hashtags are actually supported.

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?

It names clear use cases ('vetting influencers, monitoring brands or tracking competitors on Instagram'), which is well above the implied-usage bar. It stops short of 5 because it never states when not to use it or explicitly names a sibling alternative (e.g., for non-profile content on another platform).

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