get_timeline

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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), and the description adds real behavior beyond them: newest-first ordering, a hard cap of 200 rows, and the explicit boundary that it lists events, not values. It doesn't discuss truncation behavior when more than 200 events exist or whether the window is inclusive, which keeps it short of a 5.

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?

Four tightly packed sentences, front-loaded with what the tool returns, then when to use it, then the sibling boundaries, then the parameter. No filler and no repetition of 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?

An output schema exists, so return values need not be expounded, yet the description still sketches the row shape. Scope, ordering, cap, alternatives, and the sole parameter are all covered — nothing an agent needs to call this correctly is missing.

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% for the single 'days' parameter, so the description carries the full burden — and does: it states the meaning (how far back to look) and decodes the opaque default of 3650 as roughly 10 years. Nothing about the parameter is left ambiguous.

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?

Specific verb+resource: it names the chronology of health events (diagnoses, labs, visits, medications, hospitalizations, vaccinations) and states ordering and row shape. It explicitly distinguishes itself from query_observations and get_trend, so an agent can route without opening any schema.

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?

Gives concrete when-to-use context ('what happened when' questions, orienting before a visit) and explicit alternatives for adjacent needs (numbers → query_observations, direction of a marker → get_trend). This is the when/when-not/alternatives pattern in full.

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