session_close_page

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

No annotations are provided, so the description carries the burden of disclosing behavior. It clearly states the destructive action (closing a tab) and the default behavior when page_id is omitted. However, it does not mention side effects such as whether the closing is permanent, what happens if the last tab is closed, or whether any confirmation is needed. The word 'Close' implies destruction, but more transparency would improve the score.

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 one concise sentence with no filler. The primary action is front-loaded and the optional behavior is appended naturally. Every word 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 tool with one optional parameter and an output schema, the description is nearly complete. It covers the core action and the parameter default. Minor missing context includes how to identify page_id and any irreversible side effects, but these are partially inferable from sibling tools and the word 'Close.'

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. It does add meaning: page_id identifies the tab to close, and leaving it out closes the active tab. This explains the optionality and default behavior beyond the bare schema. It does not specify how to obtain a valid page_id, but the sibling session_list_pages provides that context.

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 uses a specific verb and resource: 'Close a tab.' It clearly distinguishes this from sibling tools like session_new_page, session_select_page, and browser_navigate by indicating the action of closing. The optional active-tab behavior is also stated explicitly.

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 provides clear context: use this tool when you want to close a tab, optionally specifying which one via page_id. It does not explicitly mention when not to use alternatives or list exclusions, but the scope is straightforward and unlikely to be confused with sibling actions like navigating or selecting pages.

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