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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description is not required to state that it's a safe read operation. It does add useful context by specifying the scope ('this user's') and pagination ('20 per page'), which are behavioral traits beyond the annotations. However, it doesn't discuss any other behaviors like sorting or potential performance implications, so a 3 is appropriate.

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 a single sentence that front-loads the core purpose, then mentions filters and pagination in a logical order. Every clause earns its place with no redundancy or filler. It is maximally concise while covering all essential aspects.

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 simple paginated list with a complete input schema and an output schema, the description covers the user scope, completion status, optional filters, and pagination. The output schema handles return details, and annotations handle safety. No critical information is missing for an agent to correctly invoke the 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?

The schema covers 100% of parameters with clear descriptions, so the baseline is 3. The description complements this by mentioning 'filtered by workout or exercise' and 'paginated', which aligns with the schema fields but adds little extra semantic nuance beyond what's already in the schema. No syntax or additional details are provided.

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 lists this user's completed workout sessions, making the verb and resource specific. It also mentions optional filters by workout or exercise, which distinguishes it from sibling list-workouts-tool (which likely lists workout definitions rather than history). However, it does not explicitly name a sibling to contrast against, so it stops short of a 5.

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?

There is no guidance on when to use this tool versus alternatives like get-workout-history-session-tool or list-workouts-tool. It only describes what the tool does, not the conditions that would lead an agent to choose it over siblings. No exclusions or alternative routing is provided.

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