Execute an upstream tool

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

Annotations only declare destructiveHint=false, so the description carries most of the burden and does so well: it discloses pass-through argument handling with upstream-side validation, plus timeouts, one automatic reconnect, and a circuit breaker. The retry detail is genuinely load-bearing for reasoning about non-idempotent upstream tools. It omits auth requirements and how upstream failures are surfaced as errors.

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 sentences, each doing distinct work: purpose, argument handling, failure/resilience behavior. The purpose is front-loaded and there is no filler or restatement of the title.

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?

There is no output schema, so the description should explain what a successful call returns (tool result content, shape, error form), and it does not. For a generic pass-through executor with a nested free-form arguments object, the behavioral coverage is strong but the return contract is left entirely implicit.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: arguments are passed through unmodified and validated by the upstream against a previously loaded schema. That tells the agent the local schema will not reject content and that malformed arguments fail remotely, which the schema alone does not convey.

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 opens with a specific verb and resource: "Run a tool on an upstream MCP server." That is clearly distinct from the sibling set (list_servers, list_tools, search_tools, get_tool_schema, gateway_status), but no sibling is named, so differentiation is inferable rather than explicit.

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 phrase "the schema you loaded" implies get_tool_schema should precede this call, which is a useful workflow hint, but the ordering is never stated as guidance. There is no explicit statement of when to use this versus searching/suggesting tools, and no exclusions for cases where a call should not be attempted.

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