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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds useful behavioral context beyond that: the optional date-specific text, the fallback to metadata/TOC when no section is provided, and the explicit warning that it does not return the full text. This is meaningful additional disclosure.

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 two compact sentences with no filler. The core selection mechanism and optional date are front-loaded, and the fallback behavior is clarified in the second sentence. Every phrase earns its place.

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 tool with no output schema, the description adequately covers the main return modes: section text, or metadata/time-state list/TOC. It could be more explicit about edge cases such as providing both horgony and paragrafus, but the overall behavior is clear enough for an agent to call it correctly.

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 100%, so the parameters are already documented with examples and formats. The description adds little parameter-level meaning beyond what the schema provides, which meets the baseline but does not exceed it.

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 states exactly what the tool returns: a single § of a regulation, selected by anchor or § number, optionally as in force on a given date, and without a § it returns metadata, time-state list, and table of contents. It also explicitly excludes the full text, which differentiates it from siblings like fetch.

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 clearly implies when to use the tool: for a specific section's text at a point in time, or for a regulation's metadata/TOC when no section is given. It does not explicitly name alternatives or state 'use X instead', so it stops short of full exclusionary guidance.

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