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

Annotations already set readOnlyHint=true and openWorldHint=false, covering the safety profile. The description adds useful behavioral context by disclosing the sort order ('newest first') and the included summary volume field, but it does not disclose pagination or behavior around the limit parameter. With annotations covering mutation risk, this is adequate but not rich.

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?

Two short sentences with no filler. The core action and output characteristics are front-loaded, and the optional date-range qualifier is placed at the end. Every word adds value.

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 operation with only optional parameters and an output schema, the description is mostly complete. It provides the ordering and key output facts, and the output schema handles return-value details. The main gap is that limit is not addressed, and the scope of 'sessions' (all vs. user-specific) is implicit rather than explicit.

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 0%, so the description must compensate, but it only says 'Optional date range,' which mostly restates the nullable date_from/date_to parameters. The limit parameter is not described in the schema or the description, and no format or boundary semantics for the date range are given.

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 opens with a specific verb and resource ('List sessions') and adds scoping details: newest-first ordering, summary fields with total volume, and optional date range. This clearly separates it from sibling get_session, which implies retrieving a single session.

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 intended use case is implied — call this to get a list of workout sessions, optionally within a date range. However, there is no explicit when-to-use/when-not-to-use guidance or mention of alternatives like get_session or get_stats, so the agent must infer the choice.

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