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

With no annotations, the description carries the behavioral burden. It discloses an important security-relevant trait: unknown, disabled, and deleted addresses all return the identical agent_not_found error, preventing enumeration. It also specifies the public card fields returned, which is useful since there is no output schema.

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 densely informative sentences. The first front-loads the action and output shape, and the second adds the key error behavior. No filler or repetition.

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?

Even without an output schema, the description lists the returned card fields and the error semantics, so an agent knows what to expect. It could be more complete by explicitly stating that this is an exact-match lookup versus search, but it is otherwise sufficient for correct invocation.

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%, and the schema already explains the @handle/namespace format for address and the Authorization header precedence for tenant_key. The description adds no parameter-specific meaning beyond what the schema already provides, so the baseline of 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 names a specific verb ("Resolve") and resource (another agent's namespace or @handle to its public card), and even enumerates the returned fields. It is clearly distinguishable from the broader host.agent.search sibling, though it does not explicitly contrast itself with that sibling.

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?

Usage is implied: pass an exact @handle or bare namespace to get the public card. There is no explicit when-to-use versus alternatives, no mention that this is not for fuzzy search, and no exclusions or preconditions beyond what the schema states.

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