discover_servers

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

No annotations are provided, so the description carries the full burden. It clearly implies a read-only operation by using 'scan' and 'list', and specifies the source as local config files. It does not explicitly state 'read-only' or mention any side effects, but the verbs make the passive nature clear. Lacks detail on what happens after scanning (e.g., output format), but the core behavior is transparent.

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?

Two tightly packed sentences: the first states the tool's purpose and scope, the second provides usage boundaries. No fluff or redundancy. Front-loaded with the primary action.

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 (one optional parameter, no output schema, no annotations). The description fully covers what the tool does, when to use it, and when not to. It even names the alternative. The lack of an output schema is mitigated by the description's 'list' wording, which implies the return type.

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% (the single parameter check_registry is described in the schema). The description adds no additional semantics about the parameter, but the baseline is 3 when schema coverage is high, and the parameter's purpose is clear from the schema.

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') and resource ('ALREADY INSTALLED MCP servers') with explicit sources (Claude Desktop, Cursor, Windsurf, VS Code). It clearly distinguishes from sibling tools by instructing to use check_package for install/evaluate/lookup tasks.

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 ('Use ONLY when the user wants to review/list their existing servers') and when-not-to-use ('Do NOT use this when the user wants to install, evaluate, or look up a specific package'), and names the alternative tool (check_package). This is exemplary guidance.

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