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

Goes well beyond readOnlyHint=true: warns that each BDC is read at its most recent filing so rows MIX filing dates and instructs the agent to read as_of_range before treating marks as contemporaneous. It also discloses the debt-positions-only scope, the bdc_tickers truncation at 25, the limit and min_holders caps, and the SEC EDGAR source.

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 and the example question, and every sentence carries operative information (return fields, date mixing, caps, routing, source). It is dense and slightly run-on in places, but there is no filler.

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?

With no output schema available, the description enumerates the returned fields (borrower, borrower_norm, holder_count, holder_tickers, holders, total_fair_value, total_par_amount, as_of_oldest/as_of_newest) plus units, so an agent can consume the result without guessing. All caps and defaults are stated.

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 the baseline is 3, but the description adds interpretive value by framing the set as an intersection and clarifying that min_holders governs what is SHARED rather than one book's depth. It also clarifies that bdc_tickers is truncated (not rejected) at 25, which the schema's 'max 25' does not specify.

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 resource and scope -- 'borrowers common to a GIVEN SET of BDCs' -- and crystallizes it with a concrete cross-portfolio question ('what do ARCC, OBDC and AGTC all lend to?') in one call. It is immediately distinguishable from the sibling ol_bdc_top_borrowers, which covers one BDC's book.

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?

Names the defining use case (intersection across multiple BDCs) and explicitly routes the alternative case elsewhere: 'for one BDC's book use ol_bdc_top_borrowers'. It also tells the agent what to do next -- feed a borrower_norm into ol_bdc_borrower_dispersion for cross-lender pricing.

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