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

Annotations cover only readOnlyHint=true, and the description adds substantial behavioral context beyond that: the reconciliation block semantics, the warning to read fairValueBasis before totalFairValue, the note that fairValueGap means an under-counting parse that UNDERSTATES book value, and the disclosure that figures are Oxford Ledge's parse rather than filer-published. These are exactly the caveats an agent needs to avoid misusing output.

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 scope and the key routing cue, and every clause carries information (scope, return shape, caveats). It is dense and the long run-on clause enumerating return fields is heavy, but no sentence is 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, the description must carry the return contract, and it does: {bdcs, count} plus the full per-BDC field list and the reconciliation block. Combined with the parse-fidelity caveats, an agent has everything needed to call and interpret this tool.

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?

There are zero parameters, so there is nothing to disambiguate; the description confirms 'No arguments.' Baseline for a no-param tool is 4, and no additional semantic value is possible or missing.

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: 'Roster of the ACTIVE BDCs tracked by Oxford Ledge, sorted by portfolio size.' The scoping clause 'our coverage, not the whole BDC universe' plus the named borrower-keyed sibling (search_bdc_borrower) lets an agent distinguish it from the many other BDC tools without opening a 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?

Clear usage context: active-only, wound-down issuers excluded by design, and no arguments required. It also points to the alternative (search_bdc_borrower) for borrower-keyed needs. It stops short of stating the exact condition that should route an agent to that alternative or away from the other ol_bdc_* tools, so it is slightly below full when/when-not guidance.

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