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

Annotations already declare readOnly, non-open-world, non-destructive, so safety is covered. The description adds genuinely behavioral context: it is deterministic (not predictive modelling), and it exposes the sufficient_history=false reliability signal, which an agent needs to interpret degraded results.

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-loaded with the core purpose, then supporting detail. It is dense and mostly earns its place, with minor redundancy around the repeated emphasis on 'OWN' and some listing of return contents that the output schema already carries.

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?

For a read-only analytics tool with full schema coverage and an existing output schema, the description is complete: it clarifies scope, mechanism, output character, reliability signalling, and the negative disambiguation an agent needs to select it correctly.

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 both parameters are fully documented in the schema, including the default and range. The description only restates the horizon framing and default, adding little beyond what the schema already provides; 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?

The description states a specific verb and resource (projects expected net cashflow per currency) and scope (next N weeks, from settlement history). It explicitly rules out what it is not ('NOT an FX-rate prediction'), disambiguating it from siblings like get_fx_exposure and get_fx_guidance.

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 this tool applies (deterministic statistics on the user's OWN settlement behaviour) and a strong when-not signal ('NOT an FX-rate prediction'). However, it does not name an alternative tool for the FX case, so the routing is implied rather than explicit.

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