GCP Billing and Monitoring MCP Server

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. It states the tool tests permissions but omits critical details: it doesn't specify the output format (e.g., boolean results per permission), mention rate limits, indicate if it's a read-only operation, or describe error handling. For a tool that interacts with IAM permissions, this leaves significant gaps in understanding its behavior.

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 a single, direct sentence that efficiently conveys the core function without unnecessary words. It's front-loaded with the main action ('Test which permissions'), making it easy to grasp immediately. There's no redundancy or fluff, earning a high score for conciseness.

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 tool's moderate complexity (testing IAM permissions) and the absence of both annotations and an output schema, the description is minimally adequate. It states what the tool does but lacks details on behavior, usage context, and output. While it covers the basic purpose, it doesn't fully compensate for the missing structured data, leaving gaps that could hinder effective tool selection and invocation.

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% description coverage, clearly documenting both parameters: 'project' (Project ID, defaults to current) and 'permissions' (list of permissions to test). The description adds no additional semantic context beyond what the schema provides, such as examples of common permissions or constraints on the permissions list. This meets the baseline score of 3, as the schema adequately covers parameter details.

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 purpose: 'Test which permissions the current caller has on a Google Cloud project.' It specifies the verb ('test'), resource ('permissions'), and scope ('on a Google Cloud project'), making the function unambiguous. However, it doesn't explicitly differentiate from its sibling 'gcp-iam-test-resource-permissions,' which appears to test permissions on resources rather than projects, leaving room for slight ambiguity.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., authentication), compare it to siblings like 'gcp-iam-test-resource-permissions' or 'gcp-iam-analyse-permission-gaps,' or specify scenarios where it's most applicable. This lack of context could lead to misuse or confusion among similar tools.

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