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

Annotations only declare readOnlyHint=true, so the description carries the rest and does so well: it discloses that credit limits are subtracted when the includeCreditLimitInStats setting is on, and that a degraded field lists securities or currencies that could not be priced. Both are non-obvious behavioral traits that affect how the numbers should be interpreted and would not be discoverable from the schema. It does not cover authorization or data-volume concerns, but those are secondary for a read-only stats endpoint.

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 dense sentences, front-loaded with the core return shape, then the credit-limit caveat, then the degraded-field caveat. No filler. The middle sentence's conditional could be tightened slightly, but every sentence conveys distinct information.

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 describe the return value, and it does: points over time, assets and liabilities broken out by kind, net worth in base currency, plus the degraded field for unpriced items. With only three fully-documented parameters and a read-only annotation, nothing an agent needs in order to call this correctly is missing.

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 description coverage is 100%: from/to carry inclusive YYYY-MM-DD semantics and granularity documents its enum. The description adds no further meaning to these parameters (e.g., how granularity interacts with the from/to window). Baseline 3 applies since the schema already does the work.

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 (net worth over time) and enumerates the returned structure: asset kinds, liability kinds, net worth, base currency. An agent can immediately tell this is a historical time-series of net worth rather than a point-in-time balance, which implicitly separates it from get_total_balance. It stops short of naming the closest siblings (get_balance_history, get_net_worth_drivers), so sibling differentiation is only partial.

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?

Usage is only implied by the name and the 'over time' framing plus the required granularity parameter. There is no explicit guidance on when to pick this over get_balance_history or get_net_worth_drivers, and no note about required settings or data availability. An agent must infer the routing decision from the sibling names alone.

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