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. It states the tool lists collections but doesn't mention whether this is a read-only operation, if it requires specific permissions, potential rate limits, pagination behavior, or error conditions. For a tool with zero annotation coverage, this is a significant gap in transparency.

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 and appropriately sized. It starts with a clear purpose statement, followed by organized sections for Args and Returns. Each sentence adds value without redundancy, making it easy to parse and understand 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?

Given the tool's low complexity (2 parameters, no output schema, no annotations), the description is minimally adequate. It covers the basic purpose and parameters but lacks behavioral details, usage context, and output specifics. For a simple listing tool, this is borderline acceptable but leaves gaps in completeness.

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 description adds meaningful context for both parameters: it explains that 'project_id' is 'The ID of the GCP project' and 'database_id' is 'The ID of the Firestore database (default is "(default)")'. Since schema description coverage is 0%, this compensates well by providing semantic meaning beyond the bare schema, though it doesn't cover all potential nuances like format constraints.

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: 'List collections in a Firestore database.' It specifies the verb ('List') and resource ('collections in a Firestore database'), making the action and target explicit. However, it doesn't differentiate from sibling tools like 'list_firestore_databases' or 'list_databases', which reduces clarity about when to choose this specific listing tool.

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 sibling tools like 'list_firestore_databases' or 'list_databases', nor does it specify prerequisites, exclusions, or appropriate contexts. This leaves the agent with no usage direction beyond the basic purpose.

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