ecfr_title_structure

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

The annotation already declares readOnlyHint=true, so the safety profile is covered. The description adds that the tool returns the hierarchical structure (parts, subparts, sections), which informs the agent about the return content. Since there is no output schema, this is valuable behavioral context. It does not mention potential large payloads or other edge behaviors, but for a read-only structure listing, this is sufficient.

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 compact, with a clear first sentence stating purpose, a second sentence giving usage context, and a short list of common titles. No fluff; it's front-loaded with the most important information. The list is a useful addition rather than needless padding.

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 (2 params, 1 required) and the description covers what the tool returns (parts, subparts, sections) and when to use it. The annotation covers safety. There is no output schema, but the description provides enough return information. Minor gap: it doesn't clarify whether the output is just headings or includes any metadata, but this is not critical for the tool's purpose.

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 provides 100% coverage with descriptions for both title and date. The description adds a list of common titles with their subject areas, which helps agents select an appropriate title number beyond the schema's generic range. This extra context justifies a score above the baseline.

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 the verb 'Get' and identifies the resource as 'organizational structure of a CFR title,' further specifying it 'shows all parts, subparts, and sections.' This clearly distinguishes it from siblings like ecfr_search (search) and ecfr_section (reading a specific section), especially with the note 'before reading specific sections.'

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?

It states it is 'useful for browsing what regulations exist within a title before reading specific sections,' giving a clear use case and implicitly pointing to ecfr_section as the follow-up. However, it does not explicitly name alternatives or state when not to use this tool, so it falls short of a 5.

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