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

With only readOnlyHint=true from annotations, the description carries real behavioral weight: exited positions are excluded by default and include_stale=true reveals them, default 25 lenders with a hard cap of 100, one row per lender sorted widest-spread-first with nested tranches, and the SEC EDGAR schedules-of-investments source. The units trap note ('spread' mixes percent and bps across filers; compare on spread_bps only) is exactly the kind of hazard disclosure annotations cannot provide.

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 concept and a concrete example, then the required parameter, then return shape, then the units warning and defaults — sensible ordering with no filler sentences. It is dense on a single block of prose, and the enumerated return keys are a bit listy, but each element carries information given there is no 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?

With no output schema and no rich annotations, the description compensates fully: it describes the return shape ({summary, borrower_norm, count, lender_count, tranche_count, lenders}), row granularity and ordering, the parameter sourcing path, pagination-style caps, staleness handling, units trap, and the upstream source. An agent can call this correctly without further discovery.

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 materially extends it: the units trap on spread vs spread_bps, the fact that 'spread' is the raw as-filed value, and the resolution behavior of borrower_norm (key or human name, resolved via match_type). The hard cap and nesting semantics for limit are corroborated in both places.

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 verb and resource — cross-lender loan-pricing dispersion for a single borrower — and illustrates the exact signal ('one BDC marks S+550 @ 98, another S+575 @ 99'). It is distinguishable from siblings like ol_bdc_common_borrowers, ol_bdc_mark_changes and ol_bdc_credit_quality without opening any schema.

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 routes the agent to the right source for the required key (ol_bdc_top_borrowers, search_bdc_borrower, or a raw name) and states the default/exclusion behavior for stale positions. It never explicitly contrasts itself with adjacent analysis tools such as ol_bdc_mark_changes, so the when-to-use-this-vs-that guidance is implied rather than spelled out.

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