send_message

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

No annotations provided, so description carries full burden. It discloses end-to-end encryption and that the return timestamp can be used for reactions/edits, but could mention rate limits or delivery guarantees.

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?

Three sentences effectively cover purpose, return value usage, and alternative tools/quoting guidance. Well-front-loaded and no wasted words.

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 simple message send with 4 fully described params, the description covers usage, encryption, quoting, and links to other tools. Output timestamp is explained for chaining.

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 covers all params, and description adds context: explains that quote_author and quote_timestamp are for quoting and get timestamps from get_conversation.

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 text message to a Signal contact with end-to-end encryption, and distinguishes from sibling tools like send_group_message and send_attachment.

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?

Explicitly advises using send_group_message for group chats and send_attachment for files/images, and explains how to reply/quote a message by providing quote_author and quote_timestamp from get_conversation.

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