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

Beyond the annotations (which only declare write/idempotent/not-destructive), the description discloses that extraction runs locally, enumerates supported formats (docx, spreadsheets, CSV, text/markup), notes webpages are fetched, and defines the return payload (character count) plus a failure signal (unsupported=true for PDF/PPT/images). This is rich behavioral context that the structured fields do not carry.

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 sentences, front-loaded with the purpose, followed by the mechanism and then the return/exception behavior. The format list is compact and every clause carries information an agent needs.

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 correctly supplies the return semantics (character count, unsupported=true) and the supported/unsupported format boundary. Nothing essential for calling this one-parameter tool correctly is missing.

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 coverage is 100% and the single parameter is already documented in the schema with a REF-code example. The description only restates "identified by its REF code or id," adding no syntax or format detail beyond what the schema provides, so the baseline of 3 applies.

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 gives a specific verb and resource ("Extract and persist the plain text of a Reference Library item") and names the exact mechanism it feeds (traceable_library_search). It clearly differentiates itself from the sibling search and read tools by describing the indexing/persistence act rather than retrieval.

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?

It implies the usage context well: the item becomes "searchable via traceable_library_search and cheap to read," which tells an agent this is the prerequisite step before searching or reading. It names the sibling tools but stops short of explicit when-not-to-use conditions or a direct alternative comparison.

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