library_layout

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

No annotations are supplied, so the description carries the full burden, and it does disclose 'Read-only' along with the data source (the config slotLayout) and the possible status values. It says nothing about permissions, whether the data is live from hardware or derived from configuration, pagination, or freshness, which matters for a tool meant to reflect physical state.

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?

Extremely compact, with the safety property ('Read-only') front-loaded and the rest devoted entirely to enumerating returned fields. The telegraphic fragment style ('drives and mail slots too') is slightly jarring but no sentence is filler.

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?

With no output schema, the description is the only source of return-value information, and it lists the per-slot fields and status values. However, it does not state the overall response shape (list vs. slot-keyed map), whether empty slots are included, or how drives and mail slots are labeled, leaving real gaps for a reporting tool.

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 tool takes zero parameters, so there is no parameter meaning to convey and the baseline applies. The description does not waste words on arguments and instead uses the space for return semantics.

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 enumerates exactly what the tool reports: per-slot barcode, P5 volume label/pool, target pool from the config slotLayout, and a status enum, plus drives and mail slots. The resource (library slot layout) and its contents are specific enough that an agent knows this is a layout report rather than an action. It lacks an explicit verb and never says how it differs from the similarly named 'slots' sibling, which keeps it out of 5 territory.

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?

There is no statement of when to use this versus 'slots', 'library_status', or 'library_reconcile', and no prerequisites or exclusions. The only cue is 'Read-only', which suggests a safe inspection call but does not route the agent between competing read tools.

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