mcp_discover

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

With no annotations and no output schema, the description carries the full burden and does disclose the return shape (trust tiers, install info, quality scores) and that only configured registries are searched. It omits confirming the operation is read-only and says nothing about rate limits or pagination behavior, which is why it is not a 5.

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?

Three tight sentences with no filler; purpose, return content, and the routing hint are all front-loaded before any elaboration.

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 description compensates for the missing output schema by naming what results contain, and all three parameters are schema-documented. Small gaps remain around default registry configuration and result pagination/limits beyond the schema's max.

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 query, category, and limit are already documented in the schema (baseline 3). The description adds only the registry context ('MCP Rating by default') and nothing about query syntax or category source.

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?

States a specific verb and resource ('Search the configured MCP registries ... for MCP servers') plus what comes back (trust tiers, install info, quality scores). It is clearly distinguishable from siblings like mcp_server_info, mcp_recommend, and mcp_list_active.

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?

'Use this to find servers before connecting them with mcp_connect' gives an explicit use context and names the downstream alternative. It stops short of ruling out competing discovery tools such as mcp_recommend or describing when NOT to use it.

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