SRI — MCP Server Inspector

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

With no annotations provided, the description fully discloses behavior: it reads published source, anchors observations to file:line, reports observations rather than a safety verdict, and explains that an empty result does not imply safety. It also mentions typical findings like private key access, which goes beyond basic mutation safety.

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 longer than typical but every sentence contributes value: core function, actionable timing, examples, exclusions, and limitations. It is well-structured with bold call-to-action and clear separations, making it scannable without redundancy.

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 security-sensitive tool with no output schema, the description explains expected returns (observations with citations), behavior on empty results, and coverage limits. It fully prepares the agent to invoke the tool correctly and interpret results.

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 100%, so baseline is 3. The description doesn't add significant parameter semantics beyond what's already in the schema; it reiterates that ecosystem is always 'mcp' and l402_token is free. No extra syntax or format details are provided, so it doesn't exceed baseline.

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: 'Reads the published source of an MCP server and reports what it actually does' — a specific verb and resource. It also differentiates from ordinary libraries by stating it covers only MCP servers, even though no sibling tools exist.

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?

Provides explicit when-to-use guidance: 'Call this before connecting to, installing, or invoking an MCP server you have not read yourself.' It also gives a clear exclusion: 'Do NOT call this for ordinary npm or PyPI libraries', which is strong when-not guidance.

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