list_collections

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

With no annotations provided, the description carries the full burden, and it does so well: it discloses the flat-list format, the per-entry fields, that parent_key is null for top-level collections, and the default all-library scope. It does not mention pagination, ordering, or error behavior, but for a simple read-only list tool this is adequate transparency.

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 front-loaded with the main purpose, then elegantly packs output fields, default behavior, and a cross-reference into a compact structure. Every sentence earns its place and no detail is redundant.

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 there is no output schema, the description still explains the return entry fields and hierarchy semantics, plus the single parameter. It is complete enough for an agent to call the tool correctly and interpret results. Minor omissions like pagination or result ordering do not materially hurt usability.

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 schema has 0% description coverage, so the description must compensate. It does: it explains that library_id is optional, controls scope, and points to list_libraries for valid values. This adds meaning beyond the bare schema definition of an optional integer/null parameter.

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 ('List') with a precisely scoped resource ('every collection (and sub-collection)') and even explains the intended use ('so Claude can build or walk the collection tree'). It also clarifies the output shape with parent links, making it easy to distinguish from list_items and search_library.

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 explicitly explains the default behavior ('Defaults to every library') and how to narrow it ('pass library_id (see list_libraries) to scope to just one'). It does not name alternatives to exclude, but it does reference list_libraries for valid parameter values, which is strong practical guidance.

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