GCP MCP

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

With no annotations provided, the description carries full burden but only states basic functionality. It doesn't disclose behavioral traits like pagination, rate limits, authentication requirements, error conditions, or whether this is a read-only operation (though implied by 'list'). For a GCP API tool with zero annotation coverage, this is insufficient.

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 efficiently structured with a clear purpose statement followed by Args and Returns sections. Every sentence adds value: the first states what the tool does, the second explains parameters, and the third describes the return. No wasted words or 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 list tool with 2 parameters and no output schema, the description covers basics adequately but lacks important context. Without annotations or output schema, it should ideally mention response format, pagination, or common use cases. It's minimally viable but leaves gaps for agent understanding.

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%, but the description provides clear semantic meaning for both parameters: 'project_id' identifies the GCP project, and 'network' optionally filters rules by network name. This compensates well for the schema's lack of descriptions, though it doesn't specify format details like network path structure.

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 ('List firewall rules') and resource ('in a GCP project'), with optional filtering by network. It distinguishes from siblings like 'create_firewall_rule' by focusing on listing rather than creation, but doesn't explicitly differentiate from other list tools like 'list_vpc_networks' or 'list_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 implies usage for retrieving firewall rules with optional network filtering, but provides no explicit guidance on when to use this versus alternatives like 'list_vpc_networks' or 'get_vpc_details' for network-related queries. It mentions the optional filter but doesn't explain trade-offs or prerequisites.

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