get_personal_info

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

With no annotations, the description carries the full behavioral burden. It discloses that fields without granted scopes return null, which is critical for the agent to set expectations. It also implies a read-only nature ('Get') and requires authentication implicitly via 'signed in user'. It does not mention side effects, but the null behavior is the key transparency point and is covered.

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?

Two concise sentences with zero redundancy. The first sentence states the purpose and fields; the second explains the null behavior. It is front-loaded and every sentence earns its place.

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 zero-parameter tool with an output schema, the description is complete. It lists all returned fields and explains null behavior, which is the only nuance an agent needs. The output schema presumably defines the exact format, so no further explanation is required.

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 tool has zero parameters, so the description does not need to explain them. It does add context about the returned fields, which is helpful even though it's output-related. The baseline for zero-parameter tools is 4, and the description meets that.

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?

Clearly states it gets the signed-in user's profile and enumerates the specific fields (age, weight, height, biological sex, email). This distinguishes it from sibling tools that retrieve activity, sleep, or auth data. The verb 'Get' and resource 'profile' are specific and unambiguous.

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 makes the context clear (profile data for the signed-in user), which implicitly tells the agent when to use it. However, it does not explicitly state when not to use it or name alternatives, though the specificity of the fields makes the use case obvious. Slight lack of explicit exclusions.

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