client_subscribeToChannel

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

There are no annotations, so the description carries full responsibility for behavioral disclosure. It provides no information about side effects, required permissions, session prerequisites, or what happens after subscribing. The description is essentially a tautology of the tool name, offering no added behavioral context.

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 extremely short, but this is under-specification rather than conciseness. The single sentence merely restates the tool name with a '[Client]' prefix, failing to convey any useful information beyond what is already in the tool name.

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?

Given the lack of annotations and output schema, the description should compensate by explaining the tool's place in the workflow, but it does not. It leaves the agent without enough context to understand the subscription's effects or relationship to other tools, making it incomplete for reliable tool selection and invocation.

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?

The input schema provides complete descriptions for both parameters (channelId and sessionId) with examples, and schema coverage is 100%. The description itself adds nothing about parameters, but the schema already handles semantic meaning, so a baseline 3 is appropriate.

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 'Subscribe to a channel' clearly states the action and target resource, and is distinct from sibling 'client_unsubscribeFromChannel' by being its inverse. However, it lacks specificity about what subscribing entails (e.g., receiving updates) and does not explicitly distinguish from other channel-related tools like channel_getSubscribers.

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?

No guidance is provided on when to use this tool versus alternatives, nor are any preconditions or use cases mentioned. The description simply repeats the tool's purpose without explaining the context in which subscription is appropriate.

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