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 but provides minimal behavioral information. It states it's an update operation (implying mutation) but doesn't disclose permission requirements, rate limits, whether updates are atomic/partial, error handling for failed items in batch, or what the response contains. The description doesn't contradict annotations (none exist), but fails to provide essential context for a batch mutation tool.

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 extremely concise at 6 words with zero wasted language. It's front-loaded with the core action and resource. Every word earns its place by specifying 'update' (action), 'multiple contacts' (resource and scope), and 'in a single request' (batch characteristic).

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 batch mutation tool with no annotations, 0% schema description coverage, and no output schema, the description is incomplete. It doesn't explain the complex nested parameter structure, doesn't provide usage context versus siblings, and lacks behavioral details about permissions, error handling, or response format. The schema handles parameter documentation, but the description fails to add necessary context for effective tool selection and use.

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%, so the description must compensate but doesn't. It mentions 'multiple contacts' which hints at the array structure, but provides no details about the 'inputs' parameter, required fields, property formats, or enum values for lifecyclestage/leadstatus. The schema comprehensively documents the structure, but the description adds almost no semantic value beyond implying batch processing.

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 'Update multiple contacts in a single request' clearly states the action (update) and resource (contacts), but it's vague about scope and doesn't differentiate from siblings like crm_update_contact (single update) or crm_batch_update_companies/leads/objects (other batch updates). It specifies 'multiple' and 'in a single request' which adds some context, but lacks specificity about what constitutes 'multiple' or how it differs from other batch operations.

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?

No explicit guidance on when to use this tool versus alternatives. The description doesn't mention when to choose batch update over single updates (crm_update_contact) or other batch operations (crm_batch_update_companies, crm_batch_update_leads). It also doesn't provide prerequisites, limitations, or error handling considerations for batch operations.

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