Connect GCP

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

The description goes beyond annotations by disclosing that it never changes anything in GCP, keeps credentials locally, and operates in a propose-then-confirm manner. This adds crucial context about side effects, which aligns with the readOnlyHint:false annotation (since it may write local state) and clarifies it is not destructive.

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 well-structured with a clear summary, detailed explanation, usage steps, and examples. Every sentence serves a purpose, and the information is front-loaded—the first line conveys the core function, then expands on usage and safety.

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 simplicity (one optional parameter, no output schema), the description is complete. It explains what happens with and without the parameter, reveals its safety profile (no GCP changes, local-only), and provides use-case examples, covering all necessary context for an agent to use the tool correctly.

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?

Even though the schema has 0% description coverage, the tool description fully explains the single optional parameter billing_account_id: it is the ID of the account to connect, and its absence triggers a listing behavior. This adds meaning beyond the bare schema.

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: to connect a Google Cloud billing account from within the MCP client. It uses a specific verb ('connect'), identifies the resource ('Google Cloud billing account'), and distinguishes itself from sibling tools like connect_aws and connect_azure by naming GCP explicitly.

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 explicit usage guidance: call with no arguments to list available billing accounts, then call again with billing_account_id to connect one. It also includes examples and explains the two-step flow, making it clear when to use this tool versus alternatives.

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