Post insights

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely new behavior — metric availability varies by media type, and defaults are chosen automatically unless overridden. It does not say what happens if an unsupported metric is requested (error vs. silently dropped), which is the main remaining gap.

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 short sentences, no filler, with the highest-value information (what it returns, which media types, auto-selection) front-loaded. Every sentence earns its place.

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?

With no output schema, the description usefully enumerates the returned metrics and notes the reel-specific watch time, so an agent knows what comes back. Combined with the ID provenance hint, only minor edge-case behavior (invalid metric handling, response_format mention) is left uncovered.

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?

media_id has no schema description, and the description compensates by specifying its source ('IDs come from ig_list_media') — that is exactly the missing link. It also restates the metrics override with an example matching the schema. response_format is covered by the schema and adds nothing here, which is acceptable.

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 the resource precisely: engagement metrics for 'one post, reel or story', which cleanly separates it from the account-level ig_get_account_insights sibling. The enumeration of metrics (views, reach, likes, comments, shares, saves, interactions) plus the reel-specific 'average watch time' makes the output content concrete. Not a 5 because there's no explicit verb and the per-media vs. account-level distinction is implied by 'one post' rather than stated.

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?

Gives operational guidance for both decisions an agent faces: the tool auto-selects metrics by post type, and 'pass metrics to choose your own' defines the override path. 'IDs come from ig_list_media' points to the prerequisite call. It stops short of an explicit exclusion (e.g. 'for account-wide totals use ig_get_account_insights').

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