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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false; the description's 'READ-ONLY... changes nothing' largely repeats those. The phrase 'existing OCR/fulltext' adds a mild signal that no OCR generation is triggered, but missing-content/error behavior is not disclosed.

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 and appropriately front-loaded: the read-only warning comes first, followed by a single clarifying sentence about what is returned. No space is wasted restating schema details.

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 low-complexity read-only tool, the description plus fully documented parameters and strong annotation coverage is nearly sufficient. A note about missing OCR/not-found behavior or response structure would improve it, but the absence is not blocking.

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%, including the pofid/documents_id either-or requirement and the format enum/default. The description adds no parameter-specific meaning, so the baseline 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?

States a specific operation — reading existing OCR/fulltext for a document — with the read-only nature front-loaded. This clearly differentiates it from siblings like po_documents_get and po_documents_search, which concern metadata/search rather than text extraction.

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?

Implies use when an agent needs existing document OCR or fulltext content, but never explicitly says when to prefer this tool over po_documents_get or po_documents_search. No exclusions or sibling routing are provided.

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