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

Beyond the readOnlyHint annotation, it discloses that the call costs 1 credit, that a hidden tab returns empty_result, and importantly that authorHandle refers to the poster, not the tagged account. This is meaningful behavioral context, though it doesn't cover pagination or rate-limit behavior.

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 three tight sentences with the core purpose front-loaded, followed by the authorHandle caveat and the hidden-tab behavior. No filler.

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 read-only, paginated list endpoint with no output schema, the description covers purpose, cost, edge-case behavior, and identifier options. A note on return shape or pagination expectations would make it fully complete, but it is strong for the complexity level.

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 80%, so handle, user_id, count, and cursor are already well-documented. The description reinforces the handle/user_id choice but adds no syntax or format details beyond the schema, making the baseline 3 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 states a specific verb and resource: retrieves public posts by other accounts that tagged a given profile, explicitly identifying the 'Tagged' tab. This clearly distinguishes it from siblings like instagram_userPosts or instagram_userReels.

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 clarifies that users can hide the tab (returning empty_result) and that the caller should pass either handle or user_id. It doesn't explicitly name an alternative tool or exclusion, but the 'Tagged' tab framing gives clear context for when to use it vs a standard user posts endpoint.

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