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

Beyond the annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false), the description adds genuinely useful behavior: duplicate contacts with the same email are rejected, and the call costs $0.001 but is free on failure. It does not say what a successful response contains (e.g. new record ID) or how errors surface.

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?

Three short sentences, front-loaded with the core action and object types. Slight waste: the price is stated twice ('$0.001.' then 'Costs $0.001 per call'), which is redundant phrasing rather than added information.

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 two-parameter mutation tool with a fully documented nested properties object, no output schema, and annotations covering safety, the description supplies the key non-obvious facts (duplicate-email failure, per-call cost, no charge on failure). Only the success return value and account-connection requirement are missing.

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 coverage is 100% and both parameters are documented with examples and an enum, so the schema does the heavy lifting. The description adds only the implicit link between the email-uniqueness rule and the properties payload, without naming any field or format detail.

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 states a specific verb ('Make') and enumerates the four record types (contact, company, deal, ticket) in HubSpot, which matches the enum in the schema. It is clearly distinct in intent from hubspot_get / hubspot_search / hubspot_update by name and wording, though it never explicitly names or contrasts those siblings.

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?

Creation of new records is implied but never stated as the criterion for choosing this tool over hubspot_update, hubspot_search, or hubspot_add_note. No exclusions or prerequisites (e.g. connected account, required scopes) are given, leaving the agent to infer usage from the name.

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