list_datasources

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

With no annotations present, the description carries the burden of disclosure. It explicitly marks the operation as a read using '[READ]' and lists the fields that will be returned, giving the agent a clear picture of the read-only behavior. It does not detail error conditions or configuration requirements, but for a simple list operation this is adequate.

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 concise, front-loads the read intent, and provides a single documented parameter in a clear format. Every sentence contributes useful information without unnecessary elaboration.

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 listing tool with one optional parameter and no output schema, the description covers the core purpose, return fields, and target behavior. It leaves minor gaps such as error handling for unknown targets, but overall the description is sufficient for confident invocation.

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 schema only defines 'target' as an optional string or null with a default of null, providing no semantic meaning. The description compensates by explaining that target is a 'Grafana target name from config' and that omitting it uses the default target, which is essential guidance for correctly invoking the tool.

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 begins with '[READ] Configured Grafana datasources' and lists the returned fields (id, uid, name, type, default), clearly identifying this as a read-only listing tool for datasources. This distinguishes it from sibling list tools like list_dashboards and list_rules.

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 makes the tool's purpose clear and shows the target parameter is optional, but it does not explicitly state when to prefer this tool over alternatives such as datasource_health or list_dashboards. Usage context is implied rather than explicitly contrasted with sibling tools.

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