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

Annotations already declare readOnlyHint=true, so restating read-only adds nothing, but the description contributes context the annotations cannot: the workspace scoping, the plan-tier gating requirement, and the fact that engagement only covers platforms in insightsPlatforms (i.e., some connected accounts may show no engagement). Those are non-obvious behavioral constraints an agent would otherwise miss.

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?

Three front-loaded sentences that each carry distinct information: what is returned, the platform-coverage caveat, and the plan prerequisite. The return-value enumeration is dense but not padded; nothing is repeated verbatim from the schema.

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 an output schema present, the description need not explain the response shape, and it already covers scope, plan gating, and engagement coverage limits. The only meaningful gap is the absence of guidance on choosing this over get_dashboard.

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% and the 'days' parameter already documents the allowed values (7/14/30/90) and the 30-day default in the schema itself. The description adds no further semantics about the period parameter, so this lands at the baseline.

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 read of post-performance metrics and enumerates the metric families returned (published counts, success rate, engagement, top posts, recent posts per account) scoped to the current workspace. This clearly separates it from write siblings like create_post/update_post and from list_posts, though it never distinguishes itself from get_dashboard, the closest overlapping sibling.

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?

Gives one real precondition ('Needs a plan that includes analytics') and one coverage caveat ('Engagement is read from the platforms in insightsPlatforms only'), which is useful. But it never says when to pick this over get_dashboard or list_posts, so the choice between overlapping read tools is left to inference.

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