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

Beyond readOnlyHint, it discloses verification policy (matcher-VERIFIED, >=0.9 confidence), payload limits (headline + link only, no provider summary, so false attribution cannot surface), caps and defaults for all three knobs, the empty-result semantics (items=[] is not a signal), and the DATA_UNAVAILABLE refusal path. Auth (operator-configured free API key) and cost (FREE) are also stated.

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 purpose and the operator question, then return shape, then constraints – a good information ordering with no filler. It loses a point for duplicating the schema's cap/default numbers (limit 25/100, since_days 7/90) in prose, which is redundant with the input 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?

Despite having no output schema, it documents the return shape ({summary, count, items} with per-item fields), the empty and error outcomes, the data source, and the auth requirement. An agent has everything needed to call and interpret 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 description coverage is 100%, so defaults and hard caps for limit, since_days, and min_holders are already in the schema; the description largely restates them. The one added nuance is the framing of min_holders as a cross-BDC requirement, which the schema also conveys. Baseline 3 is 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?

States a specific verb+resource+scope: 'recent VERIFIED news for the private-credit borrowers held across MULTIPLE BDCs', and pins the cross-BDC holder threshold. This clearly separates it from siblings like search_bdc_borrower (a search tool), ol_borrower_profile (entity profile), and generic get_news/search_news_archive.

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?

Frames the use case directly with the operator question 'what broke recently for the cross-BDC borrowers I should watch?', which tells an agent when this tool fits. It also warns that absence is not a signal and that an unreachable store is refused, but it never names an alternative tool or an explicit when-not condition.

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