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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered; the description adds real context beyond that: it requires a connected Phorme account (auth prerequisite), reports weights in pounds (unit convention), and discloses the no-match fallback behavior. It does not mention rate limits or latency, but that is minor.

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?

A single dense paragraph, but well front-loaded: the usage trigger and example phrasings come first, followed by return shape, safety, prerequisites, units and the fallback path. Every sentence carries information; the only near-redundancy is 'It reads only and changes nothing' against the readOnly annotation.

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?

Because an output schema exists, return-value details need not be documented, yet the description still summarizes them. It covers the aspects an agent actually needs to invoke correctly: trigger phrasing, fuzzy movement matching, auth prerequisite, units, and the no-match recovery path.

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 100%, so the baseline is 3, but the description adds meaning beyond the schema: 'finds the lift in their Phorme log by the words they use' clarifies that 'movement' is a fuzzy natural-language match rather than an exact ID, and it notes weights are in pounds, which is not encoded in 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+resource ('find the lift in their Phorme log... returns one point per session... shows a chart card') and backs it with concrete user-phrasing examples ('how is my bench going'). An agent can distinguish this analytics/charting tool from siblings like get_training_history or find_exercise_swap without opening the 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 an explicit trigger condition ('when the user asks how one of their lifts is progressing or wants it graphed') plus a worked fallback path when the lift is not matched — list logged lifts and ask which one. It does not name competing siblings (e.g. get_training_history for whole-log views), so routing against alternatives is left to inference.

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