Refresh metrics for your posts and read them in algorithm terms

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

Annotations declare readOnlyHint=true and idempotentHint=true, but the description says the tool will 'append to the local snapshot history' and return velocity/milestones. Appending to a history implies a write side effect and repeated calls may accumulate history, contradicting the read-only and idempotent hints. This is an annotation contradiction.

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?

The description is a single overloaded sentence with nested clauses, semicolons, parentheses, and multiple thresholds. It is information-dense but poorly structured and hard to parse. It could be split into front-loaded purpose, parameters, side effects, and return semantics for better readability.

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?

The description covers return values (velocity, corpus entry, cold-start lift, like milestones, aging out), side effects (snapshot history), costs, and important constraints like the 30-day limit. With no output schema, this return-value detail is valuable, though missing max semantics and possible response shape prevent a perfect score.

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?

With only 33% schema description coverage, the description compensates partially: it explains include_private_metrics, a cost difference, and the 30-day constraint on post_ids. However, max is entirely unexplained semantically; the description does not clarify what max limits (number of posts, history entries, etc.), so the low-coverage burden is not fully met.

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 opens with a specific action ('Pull current metrics for your posts') and a clear resource, then details the exact output ('return velocity + milestones'). It distinguishes itself from siblings like insights or account_pulse by focusing on algorithmic post health and concrete milestones.

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 gives clear context for when to use the tool: for own posts within 30 days, with instructions to set include_private_metrics when impressions/url clicks/profile clicks are needed. It does not explicitly name alternatives or exclusions, but the practical usage conditions are well stated.

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