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

Annotations already declare readOnlyHint, idempotentHint, closed-world, and non-destructive, so the safety profile is covered. The description adds real value beyond that: it discloses the previous-period comparison, the per-network breakdown, and the engagement-rate methodology (paired with each post's own reach for cross-network comparability). It omits caching, latency, or freshness caveats, but that is a minor 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?

A single dense sentence with three well-ordered clauses and no filler; the payload (what you get) is front-loaded before the engagement-rate caveat. It is slightly compressed for the amount of content it carries, but 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 burden of explaining return values and does so well: metric list, previous-period comparison, and per-network breakdown. What is missing is context on data freshness, timezone/period anchoring, and whether the period is anchored to today, but the core is complete for a zero-required-param analytics read.

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%, so days, platform, accountId, and workspaceId are already fully documented in the schema, including defaults and constraints. The description adds essentially no parameter-level meaning beyond the vague phrase 'per-network breakdown' and 'for the period'; the baseline 3 applies when the schema does the heavy lifting.

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 specifies the resource (aggregated performance over a period) and enumerates the payload precisely: totals per metric, previous-period totals for growth, and a per-network breakdown. This is clearly distinct from a single-metric tool, but it never names the analytics siblings (get_engagement_trend, get_follower_growth, get_top_posts) that an agent must choose between.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no alternative tool is named despite a crowded analytics neighborhood (get_engagement_trend, get_follower_growth, get_inbox_analytics, get_best_times). The scope is only implied by the returned content, leaving the agent to guess when this broad aggregate is preferred over a narrower sibling.

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