get_client_capabilities

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

With no annotations provided, the description carries the burden of behavioral disclosure. It states it 'Returns information about sampling, roots, and other client capabilities,' which clearly implies a read-only, non-destructive operation. The 'Diagnostic tool' label further signals safety. It does not mention rate limits or auth, but for a simple capability check, this is sufficient.

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 two short sentences, front-loaded with the primary purpose, and every sentence earns its place. It is concise with no filler or redundant information.

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?

The tool is simple (no params, has an output schema), and the description adequately explains what it does and what it returns. It does not need to elaborate on return values since an output schema exists. There are no prerequisites or additional context needed.

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, and the schema is empty with 100% coverage. The description adds value by explaining what the output will contain (sampling, roots, etc.), which helps an agent understand the purpose without needing parameter details. This meets the baseline for zero-parameter tools.

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 tool's purpose: 'Diagnostic tool to check what MCP capabilities the connected client supports.' The verb 'check' and resource 'client capabilities' are specific, and it is easily distinguished from sibling tools which all focus on match data retrieval.

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 by labeling the tool as 'Diagnostic' and stating it checks client capabilities. It implies use when needing to verify MCP capabilities, and no alternatives are needed since it is unique among siblings. However, it does not explicitly mention when not to use or name alternatives.

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