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

Goes well beyond annotations by disclosing the return values (actor_id, actor_token), the requirement to pass actor_token in later calls, the caveat that the session is not a credential, and the explicit scope limits (no capabilities, no Matter access, no principal verification). Annotations only mark it non-read-only; the description supplies the real behavioral profile.

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?

Front-loads the key admission gating ('[OPEN: no admission needed]') and packs routing, return values, and scope caveats into a few dense sentences with no 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?

Despite having no output schema, the description names what is returned and how to use it, and clarifies what the call does not grant. Combined with annotations, an agent has everything needed to invoke it correctly.

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 100%, so all three parameters are already documented in the schema, including the UNVERIFIED nature of 'principal'. The description adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resource ('Enroll a remote actor at this Front Door') and immediately distinguishes itself from the sibling atlas.authenticate by naming the differing method (no installation enrollment secret). An agent can select it without opening the schema.

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?

Explicitly frames when to use it ('[OPEN: no admission needed]', without the installation secret) and names the alternative path (atlas.authenticate) for the secret-based method. The routing decision between the two enrollment routes is fully spelled out.

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