gcs_get_object_metadataRetrieve metadata (size, contentType, md5Hash) for a Google Cloud Storage object without downloading its content. Check file properties before accessing data.
Fetches metadata for one object (size, contentType, md5Hash, generation, ...) without downloading its content.
| Name | Required | Description | Default |
|---|---|---|---|
| bucket | Yes | Bucket name (without gs:// prefix) | |
| object | Yes | Object path/key within the bucket |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the burden. It correctly signals a non-destructive read by saying it fetches metadata 'without downloading its content', which implies no data transfer or mutation. However, it doesn't mention permissions, error behavior for missing objects, or response shape.
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?
A single well-formed sentence with zero waste, front-loading the primary action and key distinction (metadata vs content).
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 read operation with a fully documented schema and no output schema, the description is largely sufficient: it clarifies scope (one object) and avoids confusion with download. It could be stronger by noting that the operation is read-only/non-destructive explicitly, but no critical information is missing.
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%, so both parameters are already documented. The description adds no parameter-specific details (e.g., format of object path, bucket naming conventions) beyond what the schema provides. Baseline 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?
States a specific verb (fetches) and resource (metadata for one object), and explicitly scopes it to a single object, distinguishing it from list-based siblings like gcs_list_objects. It also names concrete metadata fields, making the purpose unambiguous.
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 phrase 'without downloading its content' implicitly contrasts with gcs_download_object, but this is not framed as an explicit when-to-use rule or alternative routing. No exclusions or prerequisites are stated, leaving usage context only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.