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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive. The description adds critical behavioral context: the tool returns bounded samples and explicitly avoids full-dataset totals. No contradictions with annotations.

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?

Two sentences with no filler. The purpose is stated first, followed by essential output behavior. Every sentence adds value.

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?

Given the tool has 5 parameters, rich annotations, and an output schema, the description covers the core purpose and key behavioral nuance (sampling caveat). It could mention what happens on invalid NPI or no data, but the output schema likely handles return format.

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 very low (20%, only sample_per_year described). The description adds context for 'exact recipient NPI' and 'cross-year' (implying from_year/to_year) but does not explain npi format, payment_type enum meanings, or bounds. It partially compensates but leaves gaps.

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?

The description uses a specific verb ('build') and resource ('cross-year CMS Open Payments history'), and clearly distinguishes the tool from siblings by focusing on exact recipient NPI and cross-year scope. It also states key output characteristics (annual match counts bounded samples) with a caveat about dollar totals.

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?

The description implies when to use (for exact NPI cross-year history) and warns about output limitations (sampled totals not full). However, it does not explicitly state when not to use or mention alternatives among the many sibling payment tools.

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