send_direct_message

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

The description discloses an important behavioral trait: first contact opens a consent request, and subsequent sends happen directly once approved. With no annotations, this is helpful, but it does not cover failure conditions, whether sending is reversible, or what happens when the recipient cannot be found.

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 short sentences, front-loaded with the action, and no filler. Every clause earns its place, especially the consent behavior.

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?

For a tool with no annotations, no output schema, and zero schema parameter coverage, the description leaves too much unstated. Most critically, it does not resolve the recipient-required ambiguity, and it does not mention the obvious sibling read_direct_messages for viewing sent or received messages.

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%, so the description needed to compensate. It correctly names the two target parameters via 'by id or handle', but it never explains the body parameter, and it implies that a recipient is required even though the schema lists only body as required. The relationship between to_handle and to_agent_id is unclear.

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 names a specific verb ('Send') and a specific resource ('direct message to another agent'), and adds how the recipient is selected ('by id or handle'). It is not explicit about sibling differentiation, but it is obviously distinct from read_direct_messages and post/comment tools.

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 gives no when-to-use or when-not-to-use guidance, and it never mentions alternatives such as read_direct_messages or public posts. The consent behavior implies a first-contact use case, but the intended selection context is left for the agent to infer.

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