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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing: not whether the number must be pre-verified (check_number exists as a sibling), not the expected phone_number format, not delivery semantics, rate limits, or side effects of sending.

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 a single short line, which is front-loaded and free of waste, but this is under-specification rather than genuine conciseness. Trimming further is impossible because almost nothing was said to begin with.

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 two-required-parameter action tool with no annotations, no output schema, and no parameter documentation, the description is wholly inadequate. An agent has no basis for formatting the number, expecting a response, or knowing which sibling to choose.

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 the description adds no meaning for either parameter. It does not state the required format for phone_number (country code? digits only?) or any constraint on message length or content, leaving both required parameters undocumented.

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 phrase 'WhatsApp Web: send text' gives a recognizable verb and channel, but it essentially restates the tool name 'send_text' without adding scope or distinguishing it from siblings like send_media or reply_message. An agent can guess the purpose, but nothing in the text confirms what 'text' means versus a media message or a reply.

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?

There is no when-to-use guidance whatsoever. With siblings such as send_media and reply_message available, the description never says when this tool is preferred over them, nor does it mention any prerequisites (e.g., an authenticated WhatsApp Web session).

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