get_media_insights

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

Annotations only declare readOnlyHint and openWorldHint, and the description adds substantial context beyond them: metrics are chosen automatically per media type, unavailable metrics are reported in an `unavailable` list, data lags up to 48 hours, and carousel children return no insights. Those are exactly the surprises an agent needs to know to interpret partial results.

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?

Purpose and usage are front-loaded, then a bulleted breakdown per media type, then return shape and caveats. The metric enumerations are long but earn their space because they differ by type and set expectations for what comes back; the paragraph is otherwise tight.

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?

Covers what the agent must know to call and interpret it: where the ID comes from, type-dependent metric sets, the `unavailable`/`notes` fields, freshness lag, and the carousel exception. With an output schema present, return-value explanation is bonus rather than obligation.

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 0%, so the schema only names `media_id` as a string. The description compensates by specifying its provenance (obtain from list_recent_media) and that it identifies a single post/reel/story, which is the meaningful semantics for a one-parameter tool.

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 lifetime performance metrics') scoped to a single post, reel or story. That scoping alone separates it from the account-level sibling get_account_insights without needing to open either schema.

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?

Explicitly says 'Use this when the user asks how a specific piece of content performed' and tells the agent where the required ID comes from (list_recent_media). It never names the account-level alternative as the choice for aggregate questions, so routing is implied rather than fully spelled out.

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