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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description layers on real behavioral context: no account data is touched, the list refreshes automatically via tools/list_changed, hosted-server sessions persist enabled groups across clients, auth is none, and the UNKNOWN_GROUP error is named. This is exactly the beyond-annotations detail that prevention-of-misuse requires.

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 session-only scope and default behavior before details, and nearly every sentence carries operational value. It is dense and slightly clause-heavy, but no sentence is filler; a small trim of the hosted-server nuance would tighten it without loss.

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 no output schema, the description compensates by describing the catalogue return shape when `group` is omitted, plus auth, error token, and the full group key list. An agent has everything needed to call this correctly and interpret the result.

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% and the enum already enumerates the groups, so the schema carries the load. The description still adds meaning the schema does not: the semantics of omitting `group` (returns a catalogue with per-group summary, tool count and enabled flag) and that `all` enables everything.

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 opening clause gives a precise verb and resource: it changes which tools the connection lists, and it is session-only. That scope is unmistakably different from every sibling (agents, apps, keys, etc.), so an agent can select it 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?

It states the default state ('only core tools are listed by default'), the condition for calling it, the alternative for reaching hidden tools ('described by `search` / `fetch`'), and the distinct behavior of calling it with no `group` argument. When-to-use, when-not, and the fallback path are all explicit.

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