send_message

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

With no annotations, the description carries full responsibility. It discloses that messages go to real humans, imposes a 2000-char limit on content, warns about prompt injection, and mentions the return format (JSON string). It doesn't cover delivery guarantees or latency, but for a messaging tool this level of detail is strong.

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: a clear opening sentence, bulleted use cases, communication tips, a security warning, and parameter details. It is somewhat lengthy but each section contributes unique value. The front-loading of the primary purpose is effective, though a few tips (e.g., 'be professional') are marginally redundant.

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 the tool's moderate complexity (2 required params, no enums, output schema present), the description covers purpose, usage guidelines, parameter details, and a critical security concern. It does not need to explain return values in depth since an output schema exists. An agent has sufficient information to use this tool correctly.

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 must compensate. It explains mission_uuid as a required UUID from a mission with certain statuses, and content as a string up to 2000 chars. This adds meaningful context beyond the schema's types and titles, though it could be more explicit about UUID format (not essential).

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 opens with a clear verb+resource: 'Send a message to the worker on one of your missions.' It then enumerates specific use cases (clarify instructions, answer questions, provide context, give feedback), which distinguishes it from sibling tools like get_messages (retrieval) and approve_mission (status change).

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 explicitly states when to use the tool (after a mission is claimed, for communication purposes) and provides a security warning about when not to follow worker directives. It also includes communication tips and notes that the mission must be in specific statuses (CLAIMED, IN_PROGRESS, PROOF_SUBMITTED). This covers both usage scenarios and exclusions.

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