Get Eden Capabilities

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

Annotations already declare readOnlyHint=true and idempotentHint=true, lowering the bar. The description adds valuable behavioral context by specifying that the contract includes not just available but also conditional and unavailable operations, and that it follows 'contract 1.0'. This goes beyond a simple 'returns capabilities' statement, though it doesn't discuss error cases or session lifecycle nuances.

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, well-structured sentence that front-loads the action and resource, then packs in relevant detail about the contract's contents. No wasted words; every phrase earns its place.

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 an output schema exists, the description doesn't need to enumerate return fields. It covers the core purpose, the session context, and the semantic classes of operations. With only one optional parameter and strong annotations, the description is sufficient for an agent to understand what the tool does and when to use it.

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 0%, so the description must compensate. It does mention 'selected session', which implicitly ties to the session_id parameter, but it does not clarify the meaning of null or the default behavior. For a single optional parameter, this is adequate but not thorough; the parameter name is self-explanatory, but the null semantics remain ambiguous.

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 uses a specific verb 'Return' and identifies a clear resource: 'emulator-mcp-capabilities contract 1.0 for the selected session'. It also distinguishes the tool by detailing what the contract includes (available/conditional/unavailable operations across launch/input/capture/diagnostic), setting it apart from sibling tools like eden_get_logs or eden_get_runtime_metrics.

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 clear context: it returns capabilities for a selected session, implying use when you need to know which operations are possible for that session. However, it lacks explicit exclusions or alternatives, such as saying 'use eden_validate_launch to check launch-specific status', so it stops short of full guidance.

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