ecfr_list_titles

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

Annotations already declare readOnlyHint=true and openWorldHint=true, which cover the safety profile. The description adds that the tool returns names and last_amended_on dates, providing modest context beyond the annotations, but no additional behavioral traits like rate limits or data freshness.

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 that front-load the purpose and efficiently convey the value. Every word earns its place, with no redundancy.

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, the description explicitly states the return fields (name and last_amended_on). For a simple list-all tool, this is sufficient context. The tool's behavior is straightforward and the description covers the essentials.

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 tool has zero parameters with 100% schema coverage. Baseline for no parameters is 4, and the description does not need to add parameter details. It correctly omits any parameter explanations.

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 ('List'), resource ('all 50 CFR titles'), and includes the data fields returned (name + last_amended_on date). It clearly distinguishes from sibling tools like ecfr_search and ecfr_get_section by focusing on listing titles rather than searching within them.

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 explicitly says 'Use to discover what's in each title' and provides examples, indicating the tool is for initial exploration. It does not explicitly state when not to use it, but the context excludes the need for deeper search, which is handled by siblings.

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