get_training_readiness

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

With no annotations, the description carries the full burden and does so well: it discloses the rule-based/conservative logic, that stale data is flagged explicitly, and that a >30-minute-old sync triggers an automatic 10-40 s Garmin sync reported in the response. That auto-sync side effect and its latency are exactly the kind of behavior an agent needs before calling.

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?

Front-loaded with the verdict, then the signals, then usage routing, then behavioral caveats. Every sentence adds distinct information; nothing is restated from 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 described, and the description covers side effects, staleness, and latency. It does not state behavior when data is entirely absent or how missing signals are represented, a minor remaining gap for a diagnostic 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?

The tool takes zero parameters, which is the baseline-4 case since there is nothing to disambiguate. The description correctly implies a parameterless call and spends its space on behavior instead.

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 opens with a specific verb-and-resource pairing ('Today's readiness verdict GO / EASY / REST') and then enumerates the exact signals it aggregates (HRV, sleep, Body Battery, RHR vs 27-day baseline, ACWR, days since hard workout). This is clearly distinguished from siblings like get_recovery_summary or get_training_load, which cover single domains.

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?

It explicitly routes the agent: 'START HERE for "should I train today?"', which is a strong when-to-use signal. It does not name an alternative or a when-not condition, so it falls short of full 5-level routing guidance, but the entry-point declaration is clear.

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