List contacts

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuinely new behavioral context: that listing excludes leads by default and that contact_id is the shared identifier other tools call customer_id/vendor_id/contractor_id/employee_id. It doesn't cover pagination behavior, keeping it below a 5.

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 tight sentences: what it reads, what you get and how to narrow it, then the identifier mapping and the leads exclusion. No filler, and the core purpose is front-loaded in the first sentence.

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?

With no output schema, the description compensates by enumerating the returned fields, which is exactly what an agent needs to know. The one remaining gap is pagination behavior — the cursor's role and page-size defaults are only in the schema, not explained here.

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 75% and the description reinforces the type and search semantics, including the useful default that omitting type returns all kinds with leads excluded. It adds the cross-tool meaning of contact_id, which is not in the schema. The cursor parameter is left entirely to schema documentation.

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 ('Reads the Contractor Foreman Directory') and enumerates exactly which entity types come back (customers, employees, contractors, vendors, misc contacts) with their fields. It explicitly excludes leads and points to list_leads, so an agent can distinguish it from siblings without opening any schema.

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 clear usage context — filter by type or search by name/company/email/phone — and names the alternative for the one overlapping case ('Leads have their own tool, list_leads'). It stops short of stating when to use get_contact instead for a single record, so it's not a full when/when-not map.

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