instagram_insights

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered; the description adds genuinely useful behavioral context beyond that: the analysis window (latest 12 posts), the exclusion rule (pinned posts), and a cost of 2 credits. Cost disclosure is especially valuable for agent budgeting, though no rate-limit or failure behavior is described.

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?

Two compact, front-loaded sentences plus a cost line, with zero filler. The core metric list leads, followed by scope and exclusions, and cost last — an efficient structure where every clause 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 carries the return-value burden and does so well by enumerating the computed metrics. Combined with the 12-post window and pinned-post exclusion, an agent knows what to expect. It stops short of describing output format/units (beyond 'hours (UTC)') or behavior on private/empty profiles.

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 both parameters (user_id, username) are already fully documented in the schema, including the 'pass this or that' constraint and the @/URL acceptance for username. The description adds no additional parameter meaning, so the baseline of 3 applies.

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 names a specific analytical operation (engagement rate calculator) and enumerates exactly what it computes: mean/median engagement rate, posting cadence, format mix, best posting hours, and a benchmark percentile. This is clearly distinct from raw-content siblings like instagram_posts or instagram_profile, so an agent can route to it without opening a 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?

Usage context is implied — you call it to get engagement analytics for a profile — but there is no explicit when-to-use/when-not guidance and no alternative named (e.g., whether to prefer instagram_posts for raw data). Adequate but leaves the routing decision to inference.

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