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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the read-only nature and unpredictability of results. The description adds value by listing what is returned (names, descriptions, item counts, slugs, URLs) and advising the use of URLs for direct navigation. It does not contradict annotations and provides useful behavioral context beyond the structured metadata.

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 three sentences with no fluff. The first sentence front-loads the primary purpose and return type, the second explains the filtering option, and the third provides context and a practical usage tip. Every sentence earns its place, and the structure is efficient.

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 presence of an output schema, full parameter descriptions in the input schema, and annotations covering read-only and open-world behavior, the description is complete for an agent to call the tool correctly. It explains what the tool returns and how to use the results, leaving no critical gap for execution.

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 has 100% description coverage for all three parameters (page, limit, query), so the baseline is 3. The description mentions the keyword filter ('Optionally filter by keyword') but does not add any additional semantics about page or limit beyond what the schema already specifies. It reinforces the query parameter but adds no new information.

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 clearly states the tool's function: listing and browsing Library of Congress curated digital collections. It specifies the resource (curated collections) and the action (list/browse), and distinguishes itself from sibling tools by focusing on collections rather than item-level search or retrieval. The inclusion of concrete examples (e.g., 'Civil War Glass Negatives') further clarifies the scope.

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 provides clear context for when to use this tool—when browsing or listing curated collections—and mentions the optional keyword filter. It implies this is the entry point for discovering collections before navigating to specific items, but it does not explicitly name alternatives or state when NOT to use it (e.g., 'For item-level search, use libofcongress_search'). The usage is clear but lacks explicit exclusions.

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