Instagram Profile API

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

Annotations already give readOnlyHint=true and openWorldHint=true, so no contradiction there. The description adds real context beyond the annotations: cache behavior (0 credits on cache hit vs 2 on live read), scope exclusions (no bios, contact details, login-walled data), and the fact that it returns one object. That's meaningful over what annotations provide, but it doesn't describe pagination or error behavior, so I'm not giving a 5.

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 compact and front-loaded: it starts with the main payload and scope, then cost, then exclusions. Each sentence adds distinct information. Minor deduction because the exclusions and read-only note could be merged slightly, but it's still concise and well-structured.

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's no output schema, so the description partially covers the return shape by saying 'returns one object' and listing fields (follower/post counts). Given the tool is simple (2 params) and annotations are strong, this feels reasonably complete. It doesn't state obvious edge cases like invalid/private usernames, but for a public-data read API it's enough to call correctly.

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%, so the schema already documents both parameters clearly. The description reinforces them by tying the cost to a live read vs cache hit — that adds semantic understanding to the cache parameter beyond the schema's description. Similarly, saying 'public URL' aligns with the url param example. That's useful without duplicating the schema verbatim.

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 states a specific verb-resource pairing ('Follower and post counts for a public Instagram account'), distinct from sibling stats tools. It also explicitly scopes out private data, which shrinks ambiguity about which endpoint this is.

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 gives a clear usage context: public accounts only, and credits/cost behavior distinguishing live read vs cache hit. It doesn't name alternatives like instagram_stats or instagram_posts, so the agent isn't told exactly when to pick this over a sibling, but the platform and resource are clear enough to infer.

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