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

With no annotations, the description carries the full burden and does it well: it discloses that this is a mutating operation, the required permission, the return shape ('created resource with its absolute url'), and a meaningful behavioral caveat about consent living in the marketing sub-resource. This goes well beyond the simple verb.

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 tightly packed sentences, each earning its place: what it does, what is required/permitted, what is returned, and an important non-obvious caveat. No filler or repetition of schema details.

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 complete for a simple create tool: it states required fields, permission, return value, and a crucial compliance boundary. It does not explicitly mention organization_id in the required list, though the schema marks it required, which is a minor gap.

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 100%, so the baseline applies because the schema already documents every parameter. The description adds some context about required fields and the marketing/consent sub-resource, but it does not add meaningful meaning to individual parameters like company_id or organization_id.

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: 'Creates a contact in the tenant CRM.' It clearly distinguishes itself from sibling contact operations (get/list/update/delete) and names the minimally required fields. The scope is immediately understandable.

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 implies usage by being a create operation and mentions the required crm:write permission, but it does not explicitly state when to use this tool versus update/list or when not to use it. There are no exclusions or alternatives provided.

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