select_page

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

Annotations already declare idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context: the switch is immediate, the tab keeps its state, and out-of-range indices are errors. This goes beyond what annotations provide, though it doesn't mention what happens to the current tab or whether the selected tab becomes active in the UI.

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?

The description is two sentences with no wasted words. The core action is front-loaded, and the behavioral notes (immediate switch, state preservation, error condition) are packed efficiently. Every sentence earns its place.

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 single-parameter tool with an output schema and annotations covering idempotency and safety, the description is nearly complete. The main missing piece is the zero-based vs. one-based indexing ambiguity, which is critical for correct invocation. The reference to 'tabs' helps an agent discover the related tool, but the indexing convention should be explicit.

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 0%, so the description must compensate for the single 'index' parameter. The description explains that index refers to a tab position and that out-of-range values are errors, which adds meaning beyond the bare integer type. However, it doesn't specify whether the index is zero-based or one-based, which is a meaningful gap for a single-parameter tool.

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 states a specific verb ('Drive the tab') and resource ('at this index'), and references the 'tabs' sibling for context. It distinguishes itself from navigation tools like goto/browse by focusing on tab selection rather than URL navigation, though it doesn't explicitly name a sibling alternative.

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 description gives clear context: it operates on a tab index, the switch is immediate, and the tab keeps its state. It doesn't explicitly say when to use this vs. alternatives like goto or new_page, but the 'see tabs' reference and the focus on index-based selection imply the usage context. It also notes an out-of-range index is an error, which is a useful boundary condition.

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