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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: metrics appear only a few hours after publishing, coverage is limited to platforms Feedlio reads analytics from, and each metric set carries a last-synced timestamp. It stops short of describing empty/missing-metric behavior or error cases.

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, front-loaded with what is returned, then how to address the post. Every clause carries information — the metric list, the identifier routing, and the latency/platform caveats — with no filler.

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 correctly enumerates the returned metrics and their staleness indicator, and explains how to address the post in two different ways. It is nearly complete for a read tool; only the behavior for unsupported platforms or not-yet-synced posts is left implicit.

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 coverage is 100%, so the baseline is 3, but the description adds the crucial either/or pairing rule — post_uid alone, or platform together with platform_post_id — which the per-property schema descriptions only hint at. It does not clarify workspace_uid defaulting beyond what the schema already says.

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 resource (metrics for one published post), scopes it per account, and enumerates the returned metrics (impressions, views, reactions, comments, shares, engagements, engagement rate, last-sync time). That distinguishes it clearly from the sibling list_post_analytics and from get_post, both of which are named as identifier sources.

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?

It tells the agent exactly where each identifier comes from: post_uid from list_posts or get_post, or platform plus platform_post_id from list_post_analytics, and it warns that metrics lag a few hours and only exist for supported platforms. It does not explicitly say 'use list_post_analytics instead when you want all posts', so the routing is implied rather than stated.

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