send

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. 'Send' indicates an action but does not explain side effects, behavior if the session is not running, whether a response is returned, or whether the message is delivered asynchronously.

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 a single concise sentence that states the action and target with no filler or redundant wording. It earns every word it uses.

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 tool is simple and the schema covers both parameters, but the description omits useful operational context such as what happens when sending to a non-running session, whether output is returned, or how this relates to the session lifecycle managed by sibling tools. It is minimally viable but not complete.

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 100%, with clear descriptions for name and text. The tool description itself adds no parameter details, but the schema already documents the parameters sufficiently, so the baseline of 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 uses a specific verb and resource: 'send a message to a running session.' This clearly distinguishes it from sibling tools spawn, read, kill, and list, which create, observe, terminate, or enumerate sessions rather than interact with them.

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 'to a running session' implies the session must already exist, so an agent can infer it should be used after spawn and not for creating or killing sessions. However, it gives no explicit when-to-use guidance, exclusions, or pointers to alternative tools.

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