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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description usefully adds behavior beyond annotations: the default date window and the fact that a Cotlet API key with app access is required. It omits pagination or result-limit behavior, which keeps it from 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?

The first two sentences say essentially the same thing twice — 'Workouts ... in a date range, with completion and logged results' and 'Returns the workouts ... between two dates, each with whether the client completed it and the results they logged.' The redundancy costs space without adding information.

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?

For a read-only list tool with no output schema, the description covers what is returned, the default range, and the auth requirement, which is nearly everything an agent needs. Only pagination/result-size limits are left unaddressed.

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%, so the schema already documents client_id and both dates. The description merely restates the default range that the schema descriptions ('Default: 7 days ago' / 'Default: 7 days ahead') already carry, adding no syntax or format detail. Baseline 3 is appropriate.

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 ('workouts on a client's training calendar in a date range') plus what is returned (completion status and logged results). It is unmistakably the Everfit workout-listing tool, though it never names or distinguishes itself from a sibling alternative.

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?

'Use it to find clients with no tracked workouts' gives one concrete scenario, and the default range (last 7 days / next 7 days) is stated. However, there are no when-not-to-use conditions and no routing to any alternative tool, so usage is only implied rather than explicit.

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