List cached Docling documents

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

Annotations already cover the read-only, non-destructive safety profile, and the description reinforces this by framing the tool as pure discovery. It also discloses the empty-list edge case, which is behavior an agent needs. It doesn't discuss ordering or whether keys are stable across cache reloads, though an output schema exists to cover the return shape.

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?

Three short sentences, front-loaded with the core action, then usage context, then the edge case. No filler and nothing repeated from structured fields.

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?

For a zero-parameter read tool with annotations and an output schema, this covers everything an agent needs: what it returns, when to call it, and how to recover from an empty result.

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?

Zero parameters, so baseline is 4. The description usefully links the returned keys to the document_key argument expected by other tools, giving the agent a reason for the output even though no input semantics apply.

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?

States a specific verb and resource ('Return the keys of all Docling documents currently held in the local cache') with explicit scope (local cache, all documents). This distinguishes it from siblings like check_document_in_local_cache (single lookup) and remove_document_from_local_cache (mutation).

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?

Explicitly says when to use it ('discover which documents are available before calling any tool that requires a document_key') and what the empty-list outcome implies. It even names the two alternative entry points (convert_document_into_docling_document, create_new_docling_document) that populate the cache.

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