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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered structurally. The description adds the enddate-falls-back-to-startdate behavior, which is genuine extra context, but says nothing about return format, data sources, or pagination.

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?

A single sentence with the resource front-loaded and the range semantics in a parenthetical. No filler, nothing redundant with the schema.

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 two-parameter read tool with readOnly/openWorld annotations and no output schema, the description covers what to pass and the one non-obvious default. Only the returned data shape is unaddressed, which is minor here.

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 the baseline is 3, but the description adds a real semantic not present in the schema: enddate silently defaults to startdate. That default-resolution rule materially affects how an agent should call the tool.

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 names a specific resource (blood-pressure readings) and scope (a date or date range), so an agent immediately knows it is a read tool. It does not explicitly differentiate from siblings set_blood_pressure and delete_blood_pressure, which is why it stops short of 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?

The scope phrase 'for a date or a date range' implies the intended usage, and the enddate-default note hints at a single-day lookup. There is no explicit when-to-use/when-not guidance or mention of the write/delete siblings, so usage is only implied.

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