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

Annotations declare readOnlyHint=false and destructiveHint=false but say nothing about validation or defaults; the description adds the accepted value ranges, the integer requirement, and the `when` default of now. It stops short of saying what happens on out-of-range input or what the response contains.

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 value ranges and the `when` default are stated twice in nearly identical wording ('systolic 70-260, diastolic 40-150, pulse 20-250' then again with 'Validates ... all integers'), wasting roughly half the text. The purpose is correctly front-loaded, but the duplication is pure bloat.

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 5-parameter write tool with no output schema, the description covers the constraints an agent needs to produce a valid call, including the timestamp default. The gaps are `notes` and the lack of any statement about the return value or failure 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?

With schema description coverage at only 20%, the description carries most of the burden and does so well for systolic, diastolic, pulse and `when`. The `notes` parameter remains undocumented in both schema and description, and no measurement units (mmHg, bpm) are stated.

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 ('Records a blood-pressure reading'), which cleanly disambiguates it from get_blood_pressure and delete_blood_pressure. It even names the validated fields, so an agent knows exactly what this tool writes.

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?

There is no when-to-use guidance, no mention of the alternative blood-pressure tools (get_blood_pressure, delete_blood_pressure), and no statement about prerequisites such as existing data or overwrite behavior. Usage is only implied by the verb.

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