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

With no annotations, the description carries the full burden, and it delivers: omitted arguments leave fields unchanged, explicit null clears handle/description, taken/reserved handles fail with specific errors, handles are stored lower-case, tags and description have size caps, and contact_policy is enforced by the inbox PRD.

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?

A single dense paragraph front-loads the core action, then packs constraints, semantics, and error behavior with no wasted words. Every clause earns its place.

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?

Given five optional parameters rob and no output schema, the description covers invocation semantics, constraints, and failure modes well. The only minor gap is not describing what a successful response contains, though this is not essential 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?

The input schema already provides 100% parameter coverage with detailed descriptions, setting the baseline at 3. The description adds useful integration context like partial-update semantics and handle format, but does not substantially expand beyond what the schema already documents.

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 opens with a specific verb and resource: 'Claim or update this tenant's agent-directory card.' It names the exact fields handled and distinguishes this as the write/update sibling of read-only tools like host.agent.lookup, host.agent.search, and host.agent.whoami.

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?

The usage context is implied clearly: use this to create or modify an agent-directory profile. However, it never explicitly contrasts itself with the read-only agent tools or states when not to use it, so the routing to alternatives is left to inference.

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