Read a record

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

Annotations already declare readOnly/openWorld/idempotent/non-destructive. The description adds valuable behavioral detail: pagination via 'next_offset' and 'offset', the opt-in nature of sections, and the size trade-offs of 'full_metadata'. 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 a focused paragraph with no filler. It opens with the core purpose, then systematically explains identifier format, sections, and pagination — every sentence 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?

Given the rich input schema and presence of an output schema, the description covers the essential operational aspects: identifier variations, section selection, pagination behavior, and size guidance. No critical gaps remain.

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 coverage is 100%, so baseline is 3. The description goes beyond the schema by explaining that identifiers can carry slashes (e.g., newspaper issue naming), what each section returns, and the pagination contract for 'offset' and 'next_offset'.

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 it 'Read one Library of Congress record by its identifier, as returned by search_items or search_newspapers.' This is a specific verb+resource+identifier scope, clearly distinguishing it from the sibling search and list tools.

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 gives clear context for when to use the tool — after obtaining an identifier from a search — and offers guidance on section selection, noting 'full_metadata' is 'large and rarely needed.' It doesn't explicitly name alternative tools for when not to use, but the context is sufficient.

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