library

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 thoroughly. It explicitly states 'Read-only', that nothing here is 'ever injected, ranked against a rule, or counted toward any cap', and discloses the search fallback behavior: a search never answers 'nothing' but returns the shelf or shelf list instead. It also states what replies generally look like ('the requested listing or entry, or that fallback').

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 moderately concise and front-loaded with the primary purpose, then moves through invocation modes and behavioral caveats. Every sentence contributes useful information, though phrases like 'since the words asked with are rarely the words written' are explanatory but could be trimmed. Overall it is efficient for a tool with four optional parameters and no annotations.

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 lack of annotations and output schema, the description does a good job covering all call modes, the read-only safety profile, the fallback search behavior, and the write alternative. It does not specify exact response JSON structure or error/edge-case handling, but the four invocation modes and their replies are described well enough for an agent to select and call the tool 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 baseline is 3, and the schema already documents each parameter individually. The description adds value beyond the schema by explaining the no-arguments mode, how label narrows a shelf, how query can be scoped 'within shelf', and how parameters combine to produce different listings. This lifts it above 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 opens with a clear verb and resource: 'reads the owner's everyday knowledge' in the 'Library lane', and enumerates concrete examples like recipes, books, and expenses. It explicitly distinguishes itself from the code lane and from the sibling shelve tool ('Use shelve to write instead'). The multiple invocation modes (no args, shelf, id, query) are all tied to a clear read-only purpose.

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 explicit routing: use shelve for writes, and use this tool for reading everyday knowledge kept apart from the code lane. It also explains which call shape to use for which result ('No arguments lists the shelves...', 'shelf lists that shelf's entries', 'id returns one entry whole', 'query searches'). It does not exhaustively distinguish from other read siblings like lookup or get, but the lane separation and mode-by-mode guidance are strong.

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