list_agencies

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

With no annotations, the description carries the full transparency burden. It discloses the output type (agencies and CFR titles/chapters) and hints at the intended lookup flow, but it does not document filter matching behavior, default output when filter is null, or other edge cases.

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 concise sentences with no filler. The core function is stated first, followed by a concrete usage example. 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?

The tool is simple: one optional parameter, an output schema is present, and the description gives both the purpose and intended usage. It is nearly complete, with only minor missing details about filter semantics.

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 description coverage is 0%, so the description must compensate. It implies the filter parameter is an agency name such as 'EPA' used to find the right CFR title, but it does not explicitly define how matching works or what null does.

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 and resource: 'List federal agencies and the CFR titles/chapters they administer.' It states exactly what the tool returns and makes the tool distinguishable from siblings like search_regulations or browse_structure, which perform different tasks.

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 second sentence provides a concrete use case and sequencing: 'Use this to turn a name like EPA into the right CRT title before searching.' This clearly signals when to use the tool, though it does not explicitly describe when not to use it or name an alternative tool.

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