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

readOnlyHint already declares the safety profile, and the description adds genuinely new context: the HEALTH DATA sensitivity flag, the AND-combination semantics of filters, and the pagination contract (consume next_page, feed back as page). It stops short of describing what the response contains beyond paging, but with no output schema that is a modest gap rather than a serious one.

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?

Four short sentences, each carrying distinct information: resource scope, filter logic, paging behavior, endpoint. Everything an agent needs is front-loaded with no restatement of the title or schema fields.

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 9-parameter, zero-required read tool with full schema coverage and only readOnlyHint for annotations, the description covers the non-obvious operational concerns (AND semantics, paging, health-data sensitivity). Only the return payload shape is unspecified, and the next_page reference partially compensates.

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 per the rubric the baseline is 3; the description earns above that by adding the cross-parameter rule that filters combine with AND, which the schema cannot express per-field. It also clarifies paging mechanics, tying the opaque 'page' parameter to a next_page value an agent would not otherwise know exists.

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+resource with scope: 'List or search referrals from one healthcare provider to another,' which tells an agent exactly what domain object is returned. It does not explicitly distinguish itself from halaxy_get_referral or halaxy_list_referral_definitions, but 'list or search' vs. the singular 'get' sibling makes the split reasonably inferable.

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?

It gives actionable usage facts — 'Filters combine with AND' and 'Paged: pass next_page as page' — which guide invocation behavior. However, it never states when to use this tool rather than halaxy_get_referral (single lookup) or halaxy_list_referral_definitions, leaving sibling selection implied by naming convention only.

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