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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's job is adding semantics — and it does: the 30-day transition window, the definition of sole_trader (never scored, no band), and the addition-vs-status-change distinction. It stops short of describing result ordering for the aggregates or any size limits on the transitions list.

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?

Front-loads the headline ('Current health of the monitored portfolio') and every clause is load-bearing, including the parentheticals that define sole_trader and status change. It is a dense run-on sentence rather than cleanly separated points, which slightly hurts scannability.

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 must describe the return payload — and it comprehensively enumerates every aggregate plus the optional transitions detail and their fields. An agent has enough to call this correctly and interpret results.

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 baseline is 3, but the description goes further: it clarifies that transitions_since triggers an additional list of individual transitions with their causes, signal citation ids, and the lead register record, and that results come newest first. That adds real meaning beyond the schema's terse description.

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 (current health of the monitored portfolio) and enumerates exactly what it aggregates: status band counts, sole-trader counts, active exposure count, 30-day transitions, and overdue reviews. This is clearly distinguishable from siblings like portfolio_book and portfolio_reviews_due without opening a schema.

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?

'Start here for questions like how the book is doing or what changed since a date and why' gives clear usage context and positions it as an entry point. It also explains when to pass transitions_since (to drill into individual transitions), but it never names an alternative sibling or states when NOT to use this tool.

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