tabs_close_mcp

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

Excellent transparency: it discloses that closing the last tab empties the group and Firefox drops it, and that a later createIfEmpty creates a fresh one. It also explains that already-closed or invalid tabs are refused, giving a clear behavioral contract.

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 unnecessarily verbose, using metaphorical phrasing ('tidy up once a page has served its purpose') and repeating the 'tabs_context_mcp' source multiple times. While all content is relevant, it could be condensed to a more direct statement without losing meaning.

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?

Given the absence of an output schema, the description fully covers the tool's behavior, constraints, and edge cases (invalid IDs, last tab scenario). It provides everything an agent needs to call it correctly and anticipate outcomes.

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 covers the parameter (tabId, integer, required), and the description adds significant meaning: it must be a valid ID from tabs_context_mcp, that IDs are never reused, and that stale IDs cause refusal. This goes well beyond the raw schema.

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 clearly states the tool's function: closing a single tab by ID. The metaphorical language ('shut one tab') is still unambiguous, and the context of sibling tools (navigate, create, etc.) makes the purpose distinct.

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?

Provides concrete guidance on when to use the tool: when closing a tab, and explicitly instructs that the tabId must come from tabs_context_mcp. It also warns against invalid or stale IDs, which helps avoid misuse. However, it does not explicitly compare to siblings like tabs_create or navigate, though the action is inherently distinct.

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