zipviz_lookup

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

With no annotations, the description carries the full disclosure burden and does well: it enumerates the returned agent-card fields and, notably, warns that registrant-authored free-text fields (like description) are returned in a separate block labelled untrusted — a security-relevant behavioral detail an agent needs. It omits failure behavior for unknown domains, auth requirements, and rate limits, keeping it short of a 5.

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 tight sentences, front-loaded with the core action, and both the return contract and the untrusted-content caveat earn their place given there is no output schema.

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 one-parameter read tool with no annotations or output schema, the description compensates well by describing the return payload and its trust labelling. It is not fully complete — nothing is said about missing-domain behavior or permissions — but nothing critical to making the call is absent.

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% for the single 'domain' parameter, including a concrete example format, so the schema does the heavy lifting. The description adds only the 'by domain' framing, which the schema already conveys, 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?

The description states a specific verb and resource — 'Look up an agent on the ZipViz network by domain' — which is clearly distinct from the action-oriented siblings (send, verify, sign). It stops short of differentiating itself from the potentially overlapping zipviz_status tool, so it is clear but not fully sibling-routing.

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 when-to-use guidance, no conditions or prerequisites, and no mention of any alternative (e.g., zipviz_verify or zipviz_status). The agent must infer the usage context entirely from the verb 'look up'.

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