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

Beyond the readOnly/idempotent annotations, it discloses the window size and default, the offset chaining via next_offset, the paragraph-reflow behavior and its as_scanned exception, and that text is OCR from microfilm wrapped in an untrusted-data fence. The inclusion of the untrusted-data fencing and OCR provenance is exactly the kind of context annotations cannot 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?

Four sentences, front-loaded with what the tool returns, then when to use it, then the two behaviors that alter output (layout, next_offset), then the untrusted-data caveat. No sentence is redundant.

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?

There is no output schema, so the description carries the return-value burden and does so: it enumerates the text, prev/next ids, image reference, holding library copy, and next_offset. Nothing an agent needs to page through a document 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%, so a baseline of 3 would apply, but the description adds real meaning: it explains that limit is a character window, that offset is fed from next_offset, and that layout controls whether OCR line breaks are joined or preserved. This reinforces and contextualizes the enum choice beyond the schema's own text.

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 opening sentence names a specific resource (the OCR text of one newspaper page) and the windowing behavior, which is clearly distinct from issue-level siblings like get_issue. It does not explicitly name the sibling alternative, so sibling differentiation is inferred from scope rather than stated.

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?

"Use to read a page and turn to its neighbours" gives a clear context for invocation, and the mentions of next_offset and prev/next ids imply the pagination workflow. There is no explicit when-not guidance or named alternative such as get_issue for whole-issue reads.

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