call_tool

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

With no annotations provided, the description must disclose behavioral traits, but it only says 'Invoke a downstream MCP tool' without mentioning side effects, safety, permissions, error behavior, or whether the call is synchronous. The potential for executing arbitrary tools is a significant transparency gap.

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, both packed with relevant information. The first sentence states the purpose, the second adds essential parameter source context. No unnecessary words or repetition.

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 a generic invoker with no output schema and no annotations. The description covers the core purpose and parameter source but does not describe return values, error handling, or the behavior of the invoked tool. For a tool that can execute arbitrary downstream MCP tools, more guidance is needed to be considered complete.

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 0%, so the description must add meaning. It does clarify that server and name come from a search result of type 'tool', which helps. However, it omits any explanation of the 'arguments' parameter, even though the schema only shows it as an object/null. This partial compensation justifies a mid-range score.

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 ('Invoke') and resource ('a downstream MCP tool'), clearly distinguishing it from siblings like 'search' by explicitly saying the tool is found via search. It leaves no ambiguity about what action is performed.

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 second sentence gives clear context on when to use this tool: after a search, using server and name from a result of type 'tool'. This implies when it is appropriate, but it does not explicitly state when not to use it or mention alternatives like use_skill or route, so it falls short of a 5.

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