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

With no annotations, the description carries the full behavioral burden and does not meet it: it never states that this is a read-only operation, whether authentication or a registered agent is required, or what happens when no guardian is linked. The mode reference is the only behavioral hint offered.

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 fragment with no wasted words, which is good, but it is not front-loaded with a verb or a clear statement of what is returned. Brevity here reflects under-specification rather than disciplined conciseness.

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?

There is no output schema and no annotations, so the description should explain what the call returns (linked/unlinked, guardian identity, mode state) and any preconditions. For a status tool whose entire value is its return shape, this is a significant omission.

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 takes zero parameters, so there is nothing for the description to disambiguate beyond what the empty schema already conveys. Baseline 4 applies; the description neither adds nor detracts from parameter meaning.

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 identifies a resource (human guardian link state) and scopes it to human_passkey mode, which distinguishes it from siblings like invite_guardian or escalate_scope. However, it is a noun fragment with no verb, so an agent must infer that it is a read/status query rather than a state-changing operation.

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 explicit when-to-use guidance, no prerequisites, and no mention of alternatives such as get_account or invite_guardian. The parenthetical '(human_passkey mode)' hints at a conditional context but never states what an agent should do with it.

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