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

readOnlyHint=true already tells the agent this is a safe read. The description adds genuinely useful behavior beyond that: filters are ANDed, and pagination is done by feeding next_page back as page. It does not describe what a template record contains or response envelope, which matters somewhat since there is no output schema.

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, front-loaded sentences with no filler: purpose first, then filter semantics, then pagination mechanics and endpoint. Every clause carries information.

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 zero-required-parameter list tool this covers invocation adequately, but with no output schema the description gives no sense of what a referral template record looks like or what the paging envelope returns, leaving the agent to discover that at call time.

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 100%, so the baseline is 3, and the description earns a bump by explaining that all supplied filters combine with AND — semantics the schema does not state. The pagination sentence largely repeats the schema's own note on the page parameter.

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 ('List or search referral templates with preset properties'), which is distinguishable from the singular halaxy_get_referral_definition and from halaxy_list_referrals. It stops short of explicitly contrasting with those siblings, so it is clear but not fully differentiated.

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?

'List or search' implies when to use it, and the filter note implies narrowing, but there is no explicit guidance on when to prefer this over halaxy_get_referral_definition (fetch one known template) or halaxy_list_referrals (actual referral instances). Usage must be inferred.

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