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

Annotations only say destructive/openWorld/non-idempotent; the description adds the substantive meaning behind those flags: team-wide visibility, no delete path through the API, and duplicate names silently producing two records. That is exactly the extra context an agent needs before a non-reversible write, and it is consistent with the annotations.

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 operation class and the duplicate trap, closing with the endpoint for developers. Nothing is repeated from the title or annotations, and no sentence is filler.

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 safety story is complete, but for a 23-parameter creation tool with no output schema, the description never says what comes back (e.g., the new customer ID) or how nested contacts/locations relate to the top-level record. Adequate to call safely, thin on what to expect afterward and on the ignored-but-numerous optional fields.

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 only 26% across 23 parameters, so the description carries most of the explanatory burden — but it only touches contacts and locations, leaving high-impact fields like parent_customer, custom_fields, credit_rating, discount_type, and labor_charge_type to bare names and enums. It adds no format, ordering, or default guidance beyond the schema.

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?

Starts with an explicit operation class ("WRITE: create a customer") plus the resource and the optional sub-objects it accepts (contacts, service locations), so the agent knows exactly what it creates. It also distinguishes itself from the read-side sibling by naming servicefusion_list_customers as the lookup tool rather than a creator.

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?

Gives a concrete precondition ("search with servicefusion_list_customers first") and names the exact sibling to use, along with the consequence of skipping it (duplicate customers). It also flags that this is a write path, which separates it from all the get_/list_ siblings in the toolset.

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