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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does reveal that operations are 'signed as the key's owner,' which is useful authentication context, but it does not explain the side effects of opening/editing a passport, whether the operation is reversible, or what happens to existing passport data.

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, tight sentence that front-loads the core action and then adds the secondary edit capability. Every word contributes meaning and there is no redundancy or filler.

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 mutating tool with no annotations, no output schema, and no parameter descriptions, this is insufficient. An agent will not know what a successful call returns, what side effects to expect, or exactly how the three parameters should be combined for the open versus edit use cases.

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%, so the description must compensate. It maps 'bound key' to keyId and 'public face' to bio/displayName, adding some semantic grouping beyond the bare schema property names. However, it never names the parameters or explains their individual roles, requiredness, or constraints, so the compensation is incomplete.

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 uses a specific verb ('Open') and names a distinct resource ('a passport for a bound key'), and adds a secondary action ('edit its public face'). This is clear enough to distinguish it from siblings like get_passport, though it doesn't explicitly call out that distinction.

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 guidance on when to use this tool versus alternatives such as get_passport or bind_key. The phrase 'for a bound key' implies a prerequisite, but the description does not state it explicitly or explain what conditions would lead an agent to choose this tool.

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