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

With no annotations, the description must explain behavior, but it only states the obvious write action. It does not mention permissions, reversibility, or how contactId is used if omitted.

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 a single sentence with no redundant words, making it structurally efficient. However, it is perhaps too brief, but conciseness itself is good.

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 insufficient for a tool with no annotations or output schema. It does not explain parameter semantics or usage context, making it incomplete despite low complexity.

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 schema has 2 parameters with 0% description coverage. The description does not explain the purpose or format of 'note' or 'contactId', so it fails to compensate.

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 clearly states the tool logs a note on a HubSpot contact, using a specific verb and resource. This distinguishes it from sibling tools like hubspot_create_contact or hubspot_update_contact, as it is the only one specifically for note logging.

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 provides no guidance on when to use this tool versus alternatives, such as when to log a note vs update a contact. It lacks context about prerequisites or scenarios.

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