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

No annotations exist, so the description carries the full disclosure burden. It does disclose the key behavioral traits: the write side-effect ('store a new snapshot'), the refresh-and-return flow, and the fallback outcome for unsupported providers ('others return an unsupported snapshot'). It stops short of explaining failure/slow fetch behavior or side effects on storage, but for a mid-complexity tool the essential behavioral profile is visible.

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 sentences with zero waste: the first covers action, side effect, return value, and provider scope; the second covers routing guidance and the provider exclusion case. Information is front-loaded and 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?

For a two-parameter tool with 100% schema coverage, the description covers purpose, side effect, provider support, fallback behavior, and relationship to get_analytics; with no output schema, the return shape is only gestured at ('return it'). Slightly more detail about failure states or what the returned snapshot contains would fully close the gap, so it falls just short of complete.

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%, with postId and window already self-documenting formats and defaults ('7d (default lifetime)'). The description adds provider context that helps the agent reason about valid postId values, but it does not materially extend parameter semantics beyond the schema. Baseline 3 is appropriate because 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?

States a specific verb+resource+outcome: 'Fetch fresh analytics for a published post from the provider and store a new snapshot, then return it.' It also enumerates supported providers and explicitly differentiates from sibling get_analytics by referencing the 'last stored snapshot' vs 'current numbers' distinction. An agent can reliably tell this tool apart from the other analytics siblings.

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?

Provides explicit when-to-use guidance: 'Call this before get_analytics when you need current numbers rather than the last stored snapshot.' This names the alternative and the selection condition, leaving no inference about the main decision point. The unsupported-provider fallback note also informs whether the call is worth making at all.

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