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

Annotations already establish readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine domain context: the Epley default, the Brzycki alternative, and the reliability caveat that estimates above 10 reps are flagged as less reliable — a behavioral trait the annotations do not convey.

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?

Three compact sentences with zero filler: the core operation and output come first, then the formula default, then the reliability caveat. The key behavior (default formula) is front-loaded before optional detail.

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 carries the burden of describing returns, and it does so reasonably well by naming the percentage table and per-rep-count loads. The only gap is the exact shape/format of that table, which the agent cannot fully anticipate.

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 description coverage is 100%, and the schema already documents units, ranges, and defaults for both enums, so baseline is 3. The description restates the Epley default and adds the 10-rep reliability threshold, but adds no formula syntax or unit-handling detail beyond the schema.

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 — estimate a one-rep max from a weight × reps set — and names the concrete outputs (percentage table, per-rep-count load). This is clearly distinguishable from siblings like rpe_estimate_max or rpe_target_load, which start from RPE rather than a completed set.

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?

Usage is implied: it is the tool you call when you have a set of weight and reps and want a 1RM. There is no explicit routing guidance (e.g. when to prefer this over rpe_estimate_max) and no stated prerequisites, so the agent must infer the boundary from the description alone.

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