get_mrr_movement

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

No annotations exist, so the description carries the full behavioral burden. It does disclose the shape of the result (the four waterfall buckets), which is genuinely useful, but says nothing about read-only safety, permissions, or the 90-day cap that constrains analysis.

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 tight sentences, front-loaded with the waterfall definition and closed with the user-facing question it answers. 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?

There is no output schema, so the description must explain the return content, and it does so by enumerating the four MRR movement categories. A minor gap remains on the window boundary (calendar period vs rolling days) that period_days alone does not resolve.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents period_days with its default and bounds. The description's 'over a period' adds no format or semantics beyond that. Baseline 3 applies.

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 resource (MRR movement) and unpacks it into the exact components returned: new, expansion, contraction, churn. That decomposition clearly distinguishes it from get_mrr (a point-in-time total), but the description never names a sibling or explicitly contrasts with one.

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?

The closing question 'how did my MRR change this week/month?' gives an implied usage trigger, which is better than nothing. However, there is no guidance on when to prefer get_mrr or get_churn instead, and no stated prerequisites or exclusions.

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