Plecs Connect

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

Annotations only declare idempotentHint, so the description carries the real burden and does: it discloses the non-obvious side effect of launching the newest local PLECS install, the env-var overrides, and the polling window bounded by `startup_timeout`. Both success and failure response shapes are sketched, and the failure path points to `hints`, which an agent needs in order to recover.

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?

Front-loaded with the core action and the auto-start caveat, then the mode switch, then return shapes — a sensible order with little waste. The return-shape sentence is mildly redundant given an output schema exists, but it is short and aids error handling.

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?

With an output schema present, not detailing every return field is fine, and the description does cover the behavioral risk (spawning a process) and the escape hatch. What it leaves unexplained is the connection-targeting parameters (host/port/app_path) for a 5-parameter tool with zero schema descriptions.

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 compensate and it only partially does. `auto_start` (default, null semantics, env override) and `startup_timeout` (poll duration) are well explained, but `host`, `port`, and `app_path` get no mention at all — `app_path` is only obliquely implied by 'the newest PLECS installation'.

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 first sentence names a specific action pair (handshake/health check) and the side effect (starts PLECS when the RPC port is closed), so an agent knows exactly what this does. It never names the overlapping siblings (plecs_check, plecs_rpc, plecs_instances), so sibling differentiation is left to inference.

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?

It clearly states the condition that selects the two modes: default/`PLECS_MCP_AUTO_START=always` starts PLECS, while `auto_start=false`/`never` gives a pure health check. It does not say when to reach for this instead of `plecs_check` or `plecs_rpc`, which is the remaining gap.

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