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

Annotations already indicate readOnlyHint and idempotentHint. The description adds value by clarifying that this is read-only CGM data, not for medical decisions without clinician review, and that it supports batch execution via patient_ids. No contradiction with annotations.

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?

The description is very concise: two sentences in the first paragraph, one in the second. Every sentence adds value: it states what the tool returns, its read-only nature, usage restrictions, and bulk support. No wasted words.

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?

Given no output schema, the description lists the returned fields and warns about medical use. It covers context for a simple read tool. Bulk support is mentioned. However, missing behavioral details like error handling or data freshness could be improved. Overall adequate for a straightforward tool.

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?

With 0% schema description coverage, the description must compensate. It mentions both parameters implicitly: patient_id for single patient, patient_ids for batch. It does not detail each parameter's format, constraints, or default behavior. While it provides context, more explicit parameter documentation would improve semantics.

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?

The description clearly states it returns the latest reading with specific fields (mg_dl, trend_arrow, etc.). It identifies as a read-only CGM tool, distinguishing it from similar tools by mentioning 'latest reading' and bulk support. However, it does not explicitly differentiate from siblings like librelink_business_get_current_glucose, which might also return a current reading.

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?

The description provides context: it is intended for clinic/follower accounts and warns against using for medical decisions without clinician review. It also mentions bulk support. However, it does not explicitly state when to use this tool versus alternatives (e.g., get_current_glucose), nor does it specify prerequisites or exclusions.

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