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

Without needing annotations to carry the load, it discloses the 45-60 day EDGAR lag, fuzzy-match semantics, that `description` is a compiled public-source profile rather than filing text, the above-par mark trap, and that caveats ride in the response's tool_notes. These are behavioral traits the readOnlyHint annotation does not convey.

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?

Dense but front-loaded: the core function and the returned key lead, followed by return fields, then traps and caveats. Every clause carries information, though the telegraphic stacking of warnings is near the limit of compactness.

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 carries the full return-value burden and does so: it enumerates borrowerName, borrowerNorm, description, descriptionSource, industry, the four aggregate fields, and the per-tranche `holders` rows. Combined with pagination and miss semantics, an agent has everything needed to call it correctly.

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 meaning beyond it: it clarifies that limit/offset page `holders` only while the aggregate fields stay over CURRENT holders, and restates the 3-character minimum. This scoping clarification is the kind of detail the schema doesn't spell out.

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 precise verb+resource: 'Which BDCs lend to one private-credit borrower, matched fuzzily on name,' and names the underlying source (SEC EDGAR BDC schedules of investments, ol-derived, not filer-published). This cleanly separates it from siblings like ol_bdc_top_borrowers and search_company without opening their schemas.

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?

Gives clear situational context: it returns borrowerNorm, 'the key the ol_bdc_* tools take,' which tells the agent this is the entry point that feeds the BDC analytics siblings, and warns a miss is {found: false}, not a finding of no exposure. It stops short of naming a specific alternative tool or a when-not condition, so it's clear context without explicit routing.

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