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

Annotations already declare readOnlyHint/destructiveHint, so the safety profile is covered; the description adds substantial extra context — ordering ('newest first'), what each row contains (reps × watts, % threshold, HR drift a→b, sRPE, lactate, notes), and the HR-family exclusion rule. The fitness-interpretation caveats (4+ min reps, 8+ min bike threshold) are useful behavioral framing, though the prose is hard to parse.

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-loads the concept reasonably, but the body is a dense, jargon-laden run-on mixing return-value details, interpretation heuristics, and parameter notes without clear separation. Much of it earns its place, but the structure makes it costly to extract the actionable parts.

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, the description does the work of explaining the returned structure (per-session rows, HR drift, sRPE, lactate, notes), and adds interpretation caveats. It is nearly complete for an analytical read tool; only the 'sessions' parameter and default-8 behavior are left unexplained.

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 ~75%, and the description reinforces semantics: 'family' is a substring of the label, 'zone' filters, 'weeks' looks back (default 12, max 52). It adds the substring-matching behavior beyond the schema's example, but never mentions the 'sessions' parameter, leaving one gap.

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 opening line states the resource — 'the same rep family across sessions — the interval ledger' — and the word 'get' in the name plus the ledger framing make the read intent clear. It also distinguishes itself from the snapshot variant ('this for the longer arc and every family'), though the phrasing is idiosyncratic rather than plainly stated.

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?

Explicitly states when to use it: 'THIS IS WHERE A TARGET COMES FROM: before writing watts, a pace or a % into a rep session, read interval_progression in the snapshot ... or this for the longer arc and every family.' It routes between the two modes, though it does not name a discrete sibling tool to prefer instead.

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