Test Project IAM Permissions

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

With no annotations, the description carries the full burden. It implies a read-only evaluation via the verb 'Test', but does not explicitly state that no IAM policies are modified, what permissions are required to perform the test, or that the result is limited to the supplied permission list. This is adequate for a simple check but leaves some behavioral details implicit.

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 with no filler or repetition. It conveys the core action and scope efficiently and is easy to parse quickly.

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 two-parameter tool with a fully documented schema, the description is largely complete: it states the action, the target resource, and the subject (current caller). It lacks explicit usage guidance and a read-only guarantee, but the information needed to invoke the tool correctly is present.

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 100%, with both 'project' and 'permissions' clearly explained, including an example for permissions. The description adds no additional meaning beyond the schema, so the baseline score of 3 is appropriate.

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 uses a specific verb ('Test') and identifies the exact resource ('which permissions the current caller has on a Google Cloud project'). This clearly distinguishes it from policy-retrieval tools like get-project-policy and analysis tools like analyse-permission-gaps, while the project scope differentiates it from test-resource-permissions.

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?

There is no guidance on when to use this tool versus alternatives such as gcp-iam-test-resource-permissions or gcp-iam-validate-deployment-permissions. The description states only what it does, not when it should be selected, and provides no exclusions or alternative routing.

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