get_own_number

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

The description indicates a read operation (getting a number), which is inherently non-destructive. However, it does not explicitly state that it is read-only or safe, nor does it mention any potential side effects, authorization requirements, or rate limits. With no annotations provided, the description carries full burden but is adequate for this simple operation.

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, direct sentence with no unnecessary words. It is front-loaded with the key information. Every word earns its place, making it highly concise and structured.

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 zero parameters and no output schema, the description is mostly complete. It explains what the tool does, which is sufficient for a simple retrieval. It could be slightly improved by specifying the return value (e.g., returns the phone number as a string), but this is not critical.

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?

The input schema has zero parameters, so full schema coverage is achieved. The description adds value by clarifying that the number retrieved is the account's own number. Baseline for zero parameters is 4, and the description meets that standard.

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 the tool's function: retrieving the own Signal phone number of the account. It uses a specific verb ('get') and resource ('own Signal phone number'), distinguishing it from sibling tools like 'get_profile' or 'get_conversation'. However, it does not explicitly differentiate from other info-gathering 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?

No guidance is provided on when to use this tool versus alternatives. There is no mention of context, prerequisites, or scenarios where other tools might be preferred. This leaves the agent to infer usage from the tool's name.

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