Read text

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

Annotations already declare this as a safe, idempotent, read-only, closed-world operation, so the safety profile is covered. The description adds genuinely non-obvious behavior: a 20,000-character truncation with the result self-reporting the cut, and the fact that 'contains' does not move NVDA's cursor while nvda_find_in_page does. It stops short of describing the shape of the returned text (e.g., how the caret line is separated), but with an output schema present that is a minor omission.

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 short sentences, front-loaded with what the tool returns before the sibling routing and the truncation caveat. Every sentence carries distinct information: capability, sibling alternative, cursor side effect, and limit.

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 two-parameter read tool with full schema coverage, rich annotations, and an output schema, the description covers what an agent needs: what is returned, which sibling to prefer, the cursor side effect, and the truncation limit. Return-value formatting is correctly delegated to the output schema.

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 the baseline is 3. The description earns above baseline by adding behavioral meaning to 'contains' that the schema does not convey: the search is case-insensitive, non-cursor-moving, and scoped to the current page. The 'source' parameter's focus/navigator/review distinction is left entirely to the schema, which is acceptable given full coverage.

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 opens with a specific verb and resource: reading the full text of a document, web page, or edit field, plus the caret line. It explicitly contrasts itself with nvda_get_object_tree (content vs. controls), so an agent can distinguish it from that sibling without inspecting schemas.

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 states when to choose this over nvda_get_object_tree, and it separates the non-navigating 'contains' search from nvda_find_in_page, which moves the cursor. Both the alternative and the condition that selects each are named explicitly.

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