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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, covering the safety profile. The description adds that it returns aggregated stats and mentions optional scoping, but does not disclose additional behavioral traits such as default behavior when no parameters are given (though the schema covers that) or potential response size. Since annotations cover safety, the description provides modest extra context, justifying a 3.

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 description is two sentences with no filler. It front-loads the core purpose and then lists optional scoping. Every word earns its place, and the structure is clean and readable. It is appropriately concise for the tool's complexity.

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?

Given the tool has an output schema (not shown but indicated as present), the description need not explain return values. It covers the core purpose and all scoping options, and annotations cover safety. All parameters are optional, and the schema documents them fully. Nothing an agent needs to call it correctly is missing, making it complete for a read-only stats 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?

Schema description coverage is 100%, so the schema fully documents all six parameters, including the enum for range and the date formats. The description's mention of 'optionally scoped to a date range, workout, or exercise' summarizes the parameters but does not add meaning beyond the schema. With high coverage, a baseline of 3 is appropriate, and the description adds little extra semantic value.

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 clearly states the tool retrieves aggregated workout stats (volume, consistency, personal bests, top lifts) for the current user. It uses a specific verb ('Get') and resource ('aggregated workout stats'), and the scoping options are listed. It is unambiguous and distinguishes itself from sibling tools, which are all about creating, listing, or updating workouts.

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?

The description explicitly says stats can be optionally scoped to a date range, workout, or exercise, which implies when to use it: when aggregated stats are needed. It does not name specific alternatives or exclusions, but given the sibling list, it's clear this is the only stats tool. The guidance is clear enough for an agent to select it for stats queries, though it could be more explicit about when not to use it.

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