Send a message to a pane

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

With no annotations, the description carries the burden and discloses key behavioral traits: durable inbox, at-least-once delivery, and sender identification semantics for 'from'. These go beyond a basic description, though it does not address failure modes or permission requirements.

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 three concise sentences, front-loaded with the primary action and delivery guarantee. Each sentence adds valuable information without filler, making it efficient and well-structured.

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 no output schema and only 3 parameters, the description adequately covers what the tool does, how delivery works, and how the target reads messages. However, it does not address when to use this vs sibling tools like send_to_parent or broadcast_subtree, and does not mention prerequisites or error behavior.

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 67% with descriptions for 'to' and 'from', but 'body' lacks description. The description adds meaning for 'from' (sender should be paneId or orchestrator label) but does not clarify the 'body' parameter despite calling it 'structured'. It partially compensates for the gap.

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 clearly states the tool enqueues a structured message to a pane's durable inbox with at-least-once delivery, using the specific verb 'Enqueue' and resource 'pane's durable inbox'. It distinguishes itself from siblings by noting the target reads via read_messages or its messages resource.

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 description provides context that the target reads via read_messages or its messages resource, implying send vs receive. However, it does not explicitly state when to use send_message versus alternatives like send_to_parent or broadcast_subtree, nor does it mention any exclusions or prerequisites.

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