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

Annotations already declare readOnly/idempotent/non-destructive/non-open-world, so the safety surface is covered. The description adds real value beyond them: it says each row carries a linked-to-family-inbox flag and that emails of family members are withheld, which tells the agent not to expect contact details.

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, zero filler, with the identity and scope stated first and the exclusions last. Every sentence contributes a distinct fact (scope, included flag, withheld data).

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 simple read-only list with one optional parameter and no output schema, the description covers scope, one notable returned field, and data exclusions. It stops short of saying what other fields appear per client or whether pagination applies.

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?

Only one parameter and the schema already documents it at 100% coverage, including the 'required only if multi-agency' rule. The description adds nothing about agencyId, so the baseline 3 applies.

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 ('Lists ... clients') and narrows scope to one agency's clients, explicitly excluding other agencies' clients and family-member emails. That scoping separates it from the singular get_client sibling, though the sibling is never named.

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?

Usage is only implied: an agent can infer this is the enumerate-all endpoint versus get_client for a single record, but the description never states when to prefer one over the other or what prerequisite (multi-agency membership) triggers the agencyId parameter.

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