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

No annotations are provided, so the description carries the full burden. It discloses useful constraints ('the hub downloads it, max 10 MB', 'content_base64 max 2 MB') and the 'connected agent' requirement, but these size limits are also present in the schema. It does not mention authentication (token), failure modes, or side effects beyond sending, despite being a mutation tool.

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 short sentences, front-loaded with purpose and the key input modes, no redundant phrasing. Every sentence adds value: purpose, input options with constraints, and optional text. It is efficiently structured without wasting tokens.

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 10-parameter tool with no annotations and no output schema, the description provides the essential usage but leaves gaps. It does not cover token, expect_reply, in_reply_to behavior, or explicit prerequisites like being connected. The core send path is clear, but secondary parameters and edge behaviors are missing, making it adequate but not fully complete.

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 70%, so baseline is 3. The description adds meaningful semantics by specifying that file_id, url, and content_base64 are mutually exclusive ('Give one of') and by clarifying the 'text' parameter ('Optional text goes with it'). However, it does not explain token or expect_reply, which remain undocumented in schema and description.

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 states a specific verb ('Send'), resource ('a file'), and target ('a connected agent'), and adds 'in one step' to differentiate from a sequential upload-then-send flow. It clearly conveys what the tool does and stands apart from sibling tools like send_message, upload_file, and get_file.

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 clear input-mode guidance ('Give one of: file_id, url, or content_base64') but does not explicitly mention when to prefer this tool over siblings such as upload_file, send_message, or send_and_wait. Usage context is implied ('in one step') but no when-not or alternative tool names are provided.

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