send_message

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

With no annotations, the description carries the full burden and does disclose two important traits: the remote session is stateful ('keeps its own conversation history across calls') and it executes against its own remote filesystem, implying possible remote side effects. It does not cover auth/permission needs, timeout/failure behavior, or whether remote files may be modified, so it stops short of complete.

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 tight sentences, front-loaded with the action and its return value, followed by the state model. Nothing is redundant or padded.

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?

There is no output schema, but the description states the call returns the remote reply, and all four parameters are fully documented in the schema. The statefulness note is a valuable addition; the only gap is timeout/error semantics and confirmation of remote file side effects, which matter for a cross-machine call.

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 peer, message, timeout, and new_session each documented in the schema (including defaults and the list_peers reference). The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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 ('Send a message to the coding-agent session running on another machine') and adds the outcome ('return its reply'), which distinguishes it from the sibling list_peers. An agent can identify the operation 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?

Usage is implied by the purpose: it is the tool for talking to a remote session, with list_peers as the natural prerequisite for discovering 'peer' values. However, the description never explicitly says when to use this instead of alternatives, nor does it state exclusions or prerequisites.

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