mcp.response_format

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does not mention any traits such as input requirements (though there are none), output format, side effects, or permission needs. The agent learns only the intended action, not how it behaves or what to expect.

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 15-word sentence that includes the core action and key details. It is front-loaded with the verb 'Explain' and immediately specifies the scope. Every word serves a purpose, achieving maximum conciseness.

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 and no output schema, the description is adequate as a basic statement of purpose. However, it lacks any indication of the return value format (e.g., plain text, JSON) and only mentions two fields, leaving an agent uncertain about what exactly will be returned. A bit more detail would improve completeness.

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 input schema has 0 parameters, so schema description coverage is 100%. Per guidelines, baseline is 4. The description adds no parameter information (none needed), but it does clarify what the tool does beyond the schema, fulfilling the expectation for a parameterless 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 clearly states the tool's function: 'Explain MCP tool result fields', and specifies two concrete fields it covers ('structuredContent full payload, content[0].text summary'). This provides a specific verb+resource combination that distinguishes it from its many sibling tools, which are focused on binary analysis, memory operations, etc.

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 offers no guidance on when to use this tool versus alternatives, nor does it mention any conditions or prerequisites. It simply states the tool's function without contextualizing its place among the sibling tools. An agent would have no information about when to invoke this tool over others.

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