tabs_context_mcp

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

With no annotations, the description must disclose behavior. It states that the tool returns tab IDs but only 'if [the group] exists,' leaving unspecified what happens when no group exists (e.g., empty result, error, or creation behavior). The description does not mention the createIfEmpty parameter that controls creation, which is a significant omission.

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 appropriately sized and front-loaded with the main purpose. Each additional sentence provides critical usage rules (mandatory before other tools, new-tab policy) without waste. It is concise and impactful.

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?

The tool is simple (one optional parameter) and has an output schema. The description covers the core functionality and usage context well. The only gap is the ambiguous default behavior when no group exists and createIfEmpty is false, but the schema and output schema largely compensate for this, making the description nearly complete.

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 input schema has 100% coverage for the single parameter, with a detailed description of createIfEmpty and its effects. The description text adds no additional parameter semantics, so the baseline score of 3 applies.

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 action ('Get context information'), the resource ('current MCP tab group'), and the output ('Returns all tab IDs inside the group if it exists'). It distinguishes itself from sibling tools like tabs_create_mcp by focusing on reading context rather than creating tabs.

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 explicitly says when to use this tool ('before using other browser automation tools') and provides a clear alternative ('Each new conversation should create its own new tab using tabs_create') with an exception ('unless the user explicitly asks to use an existing tab'). This is definitive usage guidance.

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