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

readOnlyHint=true already establishes the safety profile, so the description only needs to add context. It does add a useful sensitivity flag by labeling the return as HEALTH DATA and cites the underlying endpoint GET /main/Referral/{id}, but says nothing about permissions, error behavior when the id is unknown, or result shape.

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?

Two compact sentences, both front-loaded with the operation and the data-sensitivity warning; nothing redundant or padded.

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 single-parameter read tool with no output schema and readOnly annotations already present, this covers the essentials: what it returns at a high level (a referral), that it is sensitive health data, and how to scope it. Missing only failure/not-found behavior.

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% with a pattern and a source hint for the single id parameter, so the schema carries the load. The description's 'by id' merely restates the parameter rather than adding format or sourcing detail beyond it.

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 (Fetch) and resource (a referral) plus the scoping key (by id), which separates it from the sibling halaxy_list_referrals. It does not explicitly name the sibling, so it stops short of a 5.

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?

No explicit when-to-use statement or named alternative; the id requirement implies you already have a referral id from a list call, but that routing lives in the schema parameter text ('from the matching list tool'), not the description.

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