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

Annotations already carry the safety profile (readOnlyHint, idempotentHint, destructiveHint), so the bar is lower. The description adds genuinely useful behavior beyond annotations: 'US federal only' scope, '4-hour cache' freshness constraint, 'Verified source' provenance, and the report_feedback fallback instruction. The 'No side effects / Idempotent' phrases merely restate annotations and earn no credit, preventing a 5.

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 purpose, followed by behavior flags, parameter specs, and usage routing in logical order. Every section earns its place, but the trailing report_feedback boilerplate is verbose and template-like, adding length without much unique signal. Appropriately sized overall for a 3-parameter tool with API integration.

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?

For a moderately complex search tool, nothing an agent needs to select and invoke it correctly is missing: purpose, scope, source, defaults, return fields, alternative routing, cache behavior, and failure fallback are all covered. Rich annotations and an existing output schema lower the burden on the description, which fully meets it.

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. The description adds value beyond the schema by giving richer examples for keyword ('artificial intelligence, data privacy'), an extra agency example (EPA), and explicit default behaviors ('defaults to all agencies', 'Default open'). This exceeds the baseline but stops short of 5 since the schema already documents each parameter adequately.

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 first sentence states a specific verb and resource: 'Search open rulemakings and public comment periods on Regulations.gov and the Federal Register.' It clearly differentiates from the sibling regulatory_fetch_docket_details by naming it explicitly and noting the condition that selects it (having a docket ID). The tool's scope (search vs. fetch) is unmistakable.

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?

Provides explicit when-to-use guidance ('Use this when monitoring regulatory activity on a topic') and names the exact alternative with its trigger condition ('Use regulatory_fetch_docket_details instead when you have a docket ID and need full detail'). This satisfies full when/when-not/alternative coverage.

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