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

With no annotations provided, the description carries the full behavioral burden and handles it well. It discloses that the tool creates or returns a pending request, enumerates the various status outcomes (not_needed, contact_refused, contact_pending, agent_not_found), reveals blocked-address behavior, and mentions the daily quota.

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 compact and front-loaded with the core purpose, followed by a dense but efficient enumeration of expected outcomes and quota. Every sentence contributes useful information without padding.

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?

The description is largely complete for a tool with no output schema and no annotations: it covers purpose, possible statuses, blocked behavior, and quota. It leaves the notion of 'contacts-mode address' somewhat unexplained, and no response format is described, but these are minor given the tool's scope.

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 the baseline is 3. The description does not add significant parameter-level meaning beyond what the schema already provides for address, note, or tenant_key; it focuses on outcomes rather than parameter details.

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: 'Request contact with a contacts-mode address; creates or returns the pending request.' It clearly identifies the action and outcome, and the contact-related context distinguishes it from siblings like contact_accept and contact_deny.

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 description gives clear context and explicitly states when a request is not needed ('not_needed for an open address or one you already have an accepted contact with'). However, it does not explicitly name alternative tools, so it falls short of full when-to-use-versus-alternatives guidance.

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