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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: null/unknown costs propagate as unknown, locked capital is held separately from expenditure, comparison happens only within a currency, and that the tool never fetches, pays or verifies. These are useful traits not derivable from the schema.

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?

Four tight sentences, front-loaded with the core capability and followed by constraints. Dense but no filler; every sentence carries information. Slightly compressed syntax costs it the top mark.

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 estimation tool with no output schema, the description should sketch what the result contains (per-profile totals, comparison output). It hints at comparison within a currency but never states the return shape, leaving an agent to guess the result structure.

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?

Top-level coverage is only 33% (calls and profiles have no descriptions), though the nested profile properties are richly documented. The description gestures at the inputs (prices, fees, setup costs, locked capital, batches) and clarifies unknown handling, but does not explain the meaning of calls or the workload identifier. Baseline 3 is appropriate given the nested schema does most of the heavy lifting.

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 names a specific verb and object: an exact-decimal calculation from caller-supplied prices, fees and setup costs for a planned number of calls. It adds scope detail (locked capital vs batches, same-currency comparison). It stops short of naming or contrasting any sibling such as compare_settlement_costs or cheapest_settlement_chain, so sibling differentiation is left to inference.

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 context is implied (planning a workload for a given number of calls) and the closing sentence lists clear exclusions: no exchange-rate conversion, no external fee measurement, no payment or verification. There is no explicit when-to-use vs. the settlement/RWA comparison siblings, so an agent must infer the boundary.

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