list_observation_scopes

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

The readOnlyHint annotation already declares the operation is read-only, and the description reinforces it. It adds useful behavioral detail beyond the annotation: the tool returns distinct scope dimensions from the observation store, which helps the agent understand what data to expect. No contradiction or hidden side effects are indicated.

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 compact and front-loaded: the core purpose appears in the first sentence, followed by read-only confirmation and a concrete use case. Every sentence contributes meaningful information without unnecessary detail.

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 has no parameters, an output schema is absent, and the readOnlyHint annotation covers the safety profile, the description fully covers what an agent needs to know. It explains both the output content and the intended use, leaving no critical gaps.

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 tool has zero parameters, so there are no parameter semantics to explain. The description compensates by clarifying what the return data represents, which is sufficient for an agent to invoke the tool confidently.

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 states a specific verb ('List'), the resource ('aggregate observation scopes currently retained'), and exactly what is returned ('distinct scope dimensions (source, controller, site)'). It clearly distinguishes this tool from the query_observation_trends sibling by framing it as a discovery helper for filter values.

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 explicitly tells the agent when to use this tool: 'Use to discover valid filter values for query_observation_trends.' This provides a clear, actionable usage context and links it to the relevant sibling tool without ambiguity.

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