devin_send_message

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It discloses the return shape (success/detail/error) and implies the message-sending operation. However, it doesn't state whether messages require a running/awaiting session, whether there are rate limits, or what happens if the session is already complete—modest gaps. It does add a meaningful usage trigger though.

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 well-structured and tightly written—a purpose line, a when-to-use line, and a compact Args/Returns section. No filler words or redundancy. Every sentence earns its place.

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?

Despite 0% schema coverage and no annotations, the description compensates well: it explains the use trigger, both parameters, and documents the return dict. An output schema exists (the Returns section), so return format needn't be elsewhere. For a simple 2-param message tool, the description is largely complete; only minor behavioral gaps (rate limits, session-state preconditions) keep it from 5.

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 0%, and both params have minimal schema titles ('Message', 'Session Id'). The description adds modest context: session_id is 'the session ID to message' and message is 'the message content to send.' This is marginally helpful but doesn't convey format, length constraints, or expectation that the message should be a clarification prompt—acceptable but thin.

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 it sends a follow-up message to a Devin session with a specific verb+resource ('Send a follow-up message to a Devin session'). It distinguishes from siblings reasonably—devin_run_phase runs a phase, devin_get_status/await_completion query state—while this writes a message. It's clear but doesn't explicitly contrast with siblings.

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 explicit guidance: 'Use this when Devin is blocked and needs clarification to continue.' This directly answers when to use it (unblocking a stuck session). It gives clear context but doesn't mention when NOT to use it or name alternatives explicitly, which prevents a 5.

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