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

Annotations already mark readOnlyHint=true, but the description goes beyond by detailing that it 'Never returns stored credentials', explains the `legacy_import_id` special row semantics, and notes the sync/update/rebind capabilities of file sources. It also clarifies the distinction between materialized pre-staging imports and newly staged ones, giving the agent deep behavioral context.

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 detailed and slightly long, but every sentence adds value. It front-loads the core purpose and then layers in distinctions and related-tool routing. One redundant phrase: 'a staged upload from the web wizard or layerz_import_branch { file_id }' – the reference to `layerz_import_branch` is useful, but the parenthetical could be trimmed. Overall, it is well-structured and information-dense.

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 moderate complexity (one optional parameter), the description covers purpose, usage, related tools, security implications, and edge cases (legacy imports). There is no output schema to explain, but the return row content is described in detail. An agent would know exactly when and how to call it, and what to expect back.

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 coverage is 100%, so the parameter is fully documented. The description adds contextual value by explaining that model_id is required for user-scoped keys but ignored for model-scoped keys, which is useful beyond the schema's formulation. However, this is incremental rather than essential, and the baseline is already high.

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 'List every data source feeding a model' and enumerates the types (API connectors and file imports), distinguishing it from siblings like layerz_list_branches or layerz_list_transactions. It is a specific verb+resource definition that leaves no ambiguity about what is returned.

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?

It explicitly contrasts with related tools: 'layerz_list_transactions' for browsing staged rows, 'layerz_manage_integration' for mutating, and 'layerz_delete_integration' for disconnecting. It also explains the difference between legacy imports and new staging imports, and explicitly says 'Connect a new API key from the web app' – a clear when-not-to-use signal. This is excellent guidance.

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