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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, and the description repeats these. It adds context beyond annotations by specifying 'Verified source: Federal Register API', '4-hour cache', and default date-range behavior, which help an agent understand freshness and scope. No contradiction 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?

The description is longer than average but densely informative: it front-loads the core purpose and safety traits, then covers parameters, usage, alternatives, and failure handling. Some duplication of schema content exists, but the added defaults and routing guidance justify the length.

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 output schema exists and annotations cover safety and idempotency, the description is complete for an agent to select and invoke the tool correctly. It covers what the tool returns, its source, cache behavior, defaults, the alternative tool, and a feedback fallback. Nothing essential is missing.

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?

The input schema already covers all parameters with descriptions and defaults (100% coverage), so the baseline is 3. The description adds meaningful extra semantics by stating 'defaults to last 90 days' for date_from and 'defaults to all notices' for keyword, which are not fully specified in the schema. It also repeats useful examples for each parameter.

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 opens with a specific verb and resource: 'Fetch recent Federal Register notices and rules for a specific agency.' It also immediately disambiguates scope with 'US federal only' and later names the sibling tool it is not ('regulatory_search_open_rulemakings'), so an agent can distinguish it from alternatives without opening 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?

Explicit usage guidance is present: 'Use this to monitor recent regulatory activity for an agency' states when to call it, and 'Use regulatory_search_open_rulemakings instead when filtering by topic across all agencies' states the alternative condition. It also provides a fallback feedback path if the tool does not serve the user's need.

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