fetch_blob

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 action ('fetch') but doesn't describe what 'fetch' entails (e.g., read-only operation, potential for large data transfers, authentication needs, or error handling). This leaves key behavioral traits unspecified for a tool interacting with external resources.

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, clear sentence with zero wasted words. It's front-loaded with the core action and resource, making it highly efficient and easy to parse for an AI agent.

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 complexity of fetching blobs from a registry (involving external calls, potential authentication, and data handling), the description is incomplete. With no annotations and no output schema, it lacks details on behavioral traits, return values, or error conditions, which are crucial for effective tool use in this context.

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 the schema fully documents the three parameters (digest, registry, repository). The description adds no additional meaning beyond implying these are used to locate a blob, which is already clear from the schema. This meets the baseline for high schema coverage.

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 action ('fetch') and resource ('blob referenced by a digest in a manifest'), which is specific and understandable. However, it doesn't explicitly differentiate from sibling tools like 'fetch_manifest' or 'parse_reference', which might handle similar registry/repository contexts but different resources.

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., needing a valid manifest), exclusions, or comparisons to siblings like 'fetch_manifest' for different data types, leaving the agent to infer usage from context alone.

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