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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint), so the bar is lower. The description nonetheless adds substantive behavioral context: the numbers are ESTIMATES derived from purchase price/date under lending assumptions, and per-aircraft terms override those assumptions field by field. That is exactly the interpretive context an agent needs.

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?

Two sentences, front-loaded with the returned artifacts, and every clause earns its place — the second sentence exists to qualify the estimate methodology. Slightly dense with backtick field references but not wasteful.

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?

An output schema exists, so return values needn't be explained, and annotations cover safety. The description fills the remaining gap by explaining the estimate basis and the terms-override rule, leaving little an agent needs that 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?

Only one parameter exists and schema description coverage is 100% ('From list_portfolios'), so the schema already carries the semantics. The description adds nothing about the parameter, making the baseline 3 appropriate.

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 (get) and resource (a portfolio's lender view) and enumerates the concrete outputs — estimated loan balances, estimated LTV per aircraft, book summary, watchlist. This lets an agent distinguish it from nearby portfolio tools like get_portfolio_overview or get_portfolio_positions, though it never names a sibling explicitly.

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?

There is no when-to-use guidance, no prerequisites, and no reference to alternative tools. With many overlapping portfolio tools (get_portfolio_overview, get_portfolio_positions, get_portfolio_aircraft), an agent gets no help deciding when the lender view is the right choice over those.

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