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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value by specifying the fields returned (capture date, tags, coverage notes, screen counts), which matters because there is no output schema. It stops short of noting ordering, pagination, or empty-library behavior.

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?

Two sentences, no filler, with what the tool returns front-loaded ahead of the usage hint. Every clause 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?

With zero parameters and no output schema, this is a simple read-only list tool, and the description compensates for the missing output schema by naming the returned fields. Ordering, pagination, and count limits are unstated, but for a discovery endpoint the definition is largely sufficient.

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 no parameters, so the baseline is 4. The schema is empty and there is nothing for the description to clarify; it correctly makes no parameter claims.

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 a specific verb and resource ('List every product in the library') and enumerates the data returned (capture date, tags, coverage notes, screen counts). It implies differentiation from get_product by positioning itself as the entry point, but never names a sibling explicitly.

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?

'Start here to see what references exist' gives an implied usage context as a discovery entry point, which is useful. However, it offers no explicit when-not guidance or named alternatives (e.g. get_product for a single product, search_screens for filtering), leaving routing to inference.

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