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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial context on top: what is returned, that only a free preview is available without a human-purchased licence, the underlying data provenance (CFPB HMDA 2025, actions 1-3, loan_type 2), and an explicit screening-not-misconduct caveat.

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?

Compact and front-loaded with the answering phrases and the key parameter, then the return shape. The telegraphic 'ANSWERS:/PARAM:' fragments and trailing attribution/legal lines make it dense rather than flowing, but little is truly wasted.

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 steps in to describe the return (observed vs expected denial rate, coverage flags, method version) and the licensing gate, which is what an agent needs. It omits failure modes for an invalid cohort_id and does not detail the requested_format enum.

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 67%: cohort_id and license_key are documented in-schema, but requested_format's enum has no description. The description adds partial value ('cohort id from list_cohorts', the preview/licence distinction implying license_key), yet never explains the summary vs evidence_brief choice.

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 ('Run a published cohort', returns the peer-adjusted screen: observed vs expected denial rate, coverage flags, method version), and names list_cohorts as the source of cohort_id. It never contrasts itself with the many sibling screening/stat tools (screen_counterparties, get_lender_denial_stats), so sibling differentiation is only partial.

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 explicit trigger utterances ('run the screen on <cohort>', 'how do these lenders compare against expectation') and states where cohort_id comes from (list_cohorts), plus the free-preview-vs-licence condition. It offers no when-not-to-use guidance or named alternative among the 15 siblings.

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