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

Annotations declare readOnlyHint=true, and the description does not contradict this. The description adds no additional behavioral context such as what the routing decision entails, how risky parameters are handled, or what output to expect. It mainly restates purpose and a sibling distinction, so with annotations present a neutral score of 3 is appropriate.

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 sentences and front-loads the core purpose, followed by a useful pointer to the main alternative. Every sentence earns its place with no filler or redundancies.

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?

Despite having 8 parameters and no output schema, the description offers only a purpose statement and one usage pointer. It does not explain the routing criteria, how optional constraints (max_risk, capabilities, requires_oauth, etc.) affect the result, or what the tool returns, leaving the agent without critical context for correct invocation.

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 50%, with several parameters lacking descriptions (e.g., client_target, requires_oauth, max_freshness_hours, no_write_without_approval). The tool description does not compensate by explaining any of these parameters, their relationships, or effects on routing behavior, so it adds little beyond 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 uses a specific verb and resource: 'Choose the best MCP server/tools for a task.' This clearly states the tool's purpose and distinguishes it from the sibling decide_agent_call by explicitly saying to use that tool when evaluating one specific attempted tool call.

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 gives an explicit alternative: 'Use decide_agent_call when evaluating one specific attempted tool call.' However, it does not address other potentially similar siblings like recommend_servers or search_servers, so guidance is clear for one key distinction but not comprehensive across all alternatives.

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