Close a browser session and free its resources. For a persistent session this also drops the on-disk login snapshot - idle expiry keeps it, an explicit close does not.
| Name | Required | Description | Default |
|---|---|---|---|
| session_id | Yes | Session ID |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no meaningful behavioral annotations beyond a title, the description carries the transparency burden. It discloses both resource freeing and the on-disk login snapshot side effect, contrasting explicit close with idle expiry. It could go further by mentioning what happens to the session's associated state, but the core destructive behavior is clear.
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?
Two tight sentences, front-loaded with the primary action and enriched by one important side-effect detail. Every sentence earns its place with no redundancy.
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 simple one-parameter close operation, the description is nearly complete: it states the action, the resource consequence, and the persistent-session snapshot behavior. It does not mention return values or error behavior, but those are not necessary for an agent to invoke this tool correctly.
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 schema already fully documents the single session_id parameter with 100% coverage, so the description adds no additional parameter meaning. Baseline 3 is appropriate when the schema handles parameter documentation.
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 browser session') and adds the consequence of freeing resources. It is clearly distinct from sibling session utilities like session_create, session_clone, and session_list.
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 useful context about explicit close versus idle expiry for persistent sessions, which implies when closing is appropriate. However, it does not explicitly name alternative tools or state when not to use this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools have distinct purposes, but there's overlap between session_click/click and session_eval/eval. Descriptions clarify that session_* tools operate on persistent sessions while the others are one-off, so ambiguity is low.
The session_* prefix is consistently used for session-related tools (17 of 23), while the remaining tools (cache, click, download, eval, fetch, search) are single-word lowercase verbs. This is a clear pattern, though not strictly verb_noun.
23 tools is above the typical 3-15 range but reasonable for a browser automation server that needs both one-off and session-based operations. The count is justified by the breadth of features, though it's slightly heavy.
The surface covers all major browser automation needs: navigation, clicking, typing, scrolling, screenshot, state inspection, console/network logs, cookies/storage management, JavaScript eval, waiting, and even session export. No obvious gaps for the stated purpose.