Navigator object

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds useful semantics ('same fields as nvda_get_focus') but says nothing about failure modes, such as what happens when no navigator object exists or NVDA is not running.

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?

One tight sentence with the identifying concept front-loaded and the sibling cross-reference appended; no filler, no restatement of the title.

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?

An output schema exists and annotations cover the safety profile, so the description only needs the conceptual framing, which it delivers clearly. It is slightly thin on how this relates to nearby tools such as nvda_get_object_tree or nvda_inspect_object, but nothing required to call it 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?

The single response_format parameter has 100% schema description coverage, so the schema already explains the markdown vs json trade-off; baseline 3 applies. The description contributes nothing additional about parameters, and its 'same fields' remark concerns output rather than input.

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?

Specific verb and resource ('Describe NVDA's navigator object'), with the concept explained as 'the object the user is exploring with object navigation' and explicitly contrasted against keyboard focus. The closing reference to nvda_get_focus lets an agent distinguish it from the closest sibling without opening either schema.

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?

The clause 'which can differ from the keyboard focus' implicitly tells the agent when this tool is the right one (object-navigation position rather than focus), but there is no explicit when/when-not statement or a direct 'use nvda_get_focus instead if...' routing instruction. Usage is inferable rather than stated.

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