attach_test_client

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

No annotations are provided, so the description carries the burden. It discloses important behavior beyond schema: it attaches without owning the process, the returned handle status records attached=true and owns_process=false, and the MCP server records the endpoint as the active attached context for replay-backed tools. It still omits auth/error behavior, timeout semantics, and conflict handling for multiple attaches.

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 short paragraphs, with the core purpose front-loaded in the first sentence and useful context following. There is no filler or repetition, and the agent can parse the key points quickly.

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 output schema exists and the description adds usage context, but with three undocumented parameters and no annotations, the definition leaves gaps around parameter roles, timeout behavior, and failure modes when the endpoint is not listening. It is minimally viable but not complete for an attach operation that changes active MCP context.

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% for three parameters, so the description should compensate. It does not explain host, port, or connect_timeout_sec; it only alludes to default host/port in the context of replay-backed tools, leaving the actual parameters undocumented. This is well below adequate for a low-coverage 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?

States a specific verb and resource—attach to an already-listening /TESTCLIENT endpoint—and immediately distinguishes it from process-owning siblings by saying 'without owning its process.' An agent can select this over launch_test_client/stop_test_client without opening the schema.

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?

Gives a clear when-to-use condition: clients started out-of-band, such as with a custom environment or host-side launcher. It does not explicitly name the alternative tool (e.g., launch_test_client) or state when not to use this, but the context is strong enough to guide selection.

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