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

Annotations already declare the tool as readOnly (hint: true), idempotent (hint: true), and non-destructive (hint: false), so the description's burden is lower. It adds useful context about the time window (72 hours) and the risk factors considered (corridor stability, FX session liquidity, etc.), but does not disclose what happens if the LEI is invalid or if the amount exceeds $5M beyond mentioning 'splitting guidance.' No contradiction with annotations.

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?

The description is information-dense but efficient, covering purpose, output structure, and usage guidance in two sentences. It is front-loaded with the core purpose and risk factors. However, it could be slightly more concise by trimming the detailed output format (e.g., 'OPTIMAL/GOOD/ACCEPTABLE/AVOID') which is already implied by the output schema.

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?

Given the tool's moderate complexity (5 parameters, 2 required) and a rich output schema, the description adequately covers the tool's purpose and key behaviors. It explains the risk factors and large-amount guidance, which are not in the schema. Minor gap: does not mention pagination or the response format beyond classification, but the output schema likely handles that.

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%, so the baseline starts at 3. The description adds significant semantic value by explaining the 'amount' parameter's role in large-amount guidance ($5M threshold) and the 'lei' parameter's purpose (ESG tier lookup for counterparty risk penalty), which goes beyond the schema's minimal 'optional 20-char GLEIF LEI' 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?

The description uses a specific verb ('analyzes') and resource ('settlement execution window'), clearly stating it generates 18 × 4-hour time slots scored by multiple risk factors. It distinguishes itself from siblings like stability.corridor (which likely focuses on corridor stability alone) and oracle.stability (which may be a broader stability oracle).

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 description explicitly advises 'Use this before scheduling large cross-border settlements to minimize execution risk,' providing clear when-to-use guidance. However, it does not explicitly state when not to use it (e.g., small amounts) or mention alternatives among siblings, such as settlement.quote or fx.rate for immediate execution.

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