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

With annotations already marking this as non-read-only, the description adds meaningful behavioral detail: the note appears on the contact/listing timeline and an agency API key is required. This goes beyond the schema and annotations without contradicting them.

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?

Every sentence earns its place: purpose, required inputs, attachment behavior, and authentication requirement. The description is short, front-loaded, and immediately actionable.

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?

Covers the key operational facts an agent needs: target type, input source, result of the action, and authentication. It does not describe return values or error cases, but for a simple logging action with a clear input schema, the description is sufficiently complete.

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?

Input schema coverage is essentially complete for all parametersley, so the baseline applies. The description adds modest value by clarifying that contact_id comes from find_contacts and that the target can be a contact and/or property, but it does not significantly extend the schema semantics.

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: 'Log a note against a contact or a listing in your agency's CRM.' The examples (call outcome, viewing) and attachment targets make the tool's purpose immediately clear and distinguish it from sibling tools that create contacts/listings or submit enquiries.

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?

Gives clear context on when to use the tool and what inputs it needs, including that contact_id should come from find_contacts and that either a contact_id or property_reference can be used. It does not explicitly exclude alternatives or state when not to use this tool, but the context is strong enough.

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