GCP MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. While it indicates this is a read operation ('List'), it doesn't mention important behavioral aspects like authentication requirements, rate limits, pagination behavior, error conditions, or what format the returned subnet data will have. The description is minimal beyond stating the basic operation.

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 perfectly structured with a clear purpose statement followed by well-organized Arg/Return sections. Every sentence earns its place with zero wasted words, and the information is front-loaded with the most important details first.

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 read operation with 2 parameters and no output schema, the description covers the basic purpose and parameters adequately. However, without annotations and with no output schema, it should ideally provide more behavioral context about what the returned subnet data includes, authentication requirements, or error handling to be fully 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?

With 0% schema description coverage, the description compensates well by clearly explaining both parameters: 'project_id' as 'The ID of the GCP project' and 'region' as 'Optional region to filter subnets by'. This adds meaningful semantic context beyond the bare schema, though it doesn't provide format examples or constraints for either parameter.

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 specific action ('List subnets'), target resource ('in a GCP project'), and optional scope ('optionally filtered by region'). It distinguishes itself from sibling tools like list_vpc_networks or list_compute_instances by focusing specifically on subnets.

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 about when to use the tool ('list subnets in a GCP project') and mentions the optional filtering capability. However, it doesn't explicitly state when NOT to use it or name specific alternatives among the sibling tools for different subnet-related operations.

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