HubSpot MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states this is an update operation (implying mutation), but doesn't mention permissions required, whether changes are reversible, rate limits, or what happens to existing preferences not mentioned. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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, efficient sentence that gets straight to the point with zero wasted words. It's appropriately sized for what it communicates, though it could benefit from additional context given the complexity of the operation.

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?

For a mutation tool with 3 parameters (including a nested object), 0% schema description coverage, no annotations, and no output schema, the description is inadequate. It doesn't explain what the tool returns, what permissions are needed, how to structure the preferences object, or how this differs from similar sibling tools. The agent would struggle to use this tool correctly.

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 0%, meaning all 3 parameters are undocumented in the schema. The description mentions 'communication preferences' which hints at the 'preferences' parameter, but doesn't explain what 'contactId' or 'subscriptionId' represent, nor does it clarify the structure of the preferences object. The description adds minimal value beyond what's implied by parameter names.

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 action ('Update') and target ('communication preferences for a contact'), which is specific and unambiguous. However, it doesn't differentiate from sibling tools like 'communications_update_subscription_status' or 'communications_subscribe_contact', leaving some ambiguity about when to choose this tool over those alternatives.

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 like 'communications_update_subscription_status' or 'communications_subscribe_contact'. There's no mention of prerequisites, context, or comparison with sibling tools, leaving the agent to infer usage from the tool name alone.

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