get_body_age

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered without the description. The description does add return-shape context beyond annotations (range, components, levers, missing inputs, trend), which is genuinely useful for a tool with no output schema. It still omits date format, timezone, and behavior when the date is omitted.

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?

One compact sentence with the retrieval rule front-loaded before the colon-delimited list of outputs. No filler, though the fragment style is terse to the point of being slightly cryptic.

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?

With no output schema present, enumerating the return contents (range, components, levers, missing inputs, trend) is the right move and largely discharges that burden. What remains missing for a one-param metric tool is the date acceptance format and the default-when-omitted 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 0% and the single 'date' parameter has no description, so the burden falls on the description. 'On or before the date' usefully establishes that the date is an upper bound rather than an exact-match filter, but the expected format and the null/default behavior remain undocumented.

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 resource ('body age') and a precise retrieval semantic ('latest ... on or before the date'), which is enough to tell it apart from the other get_* metric tools. It stops short of naming any sibling for comparison, so it sits at a clear-but-undifferentiated 4.

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 statement of when this is preferable to get_trends or get_overview, and no conditions or prerequisites. Usage is only implied by the resource name.

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