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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered elsewhere. The only added context is the implicit tenancy scoping ('the trainer's gym'), which largely restates the title 'See my gym units' — nothing about ordering, completeness, or whether inactive units are included.

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 front-loaded sentence with zero waste. It is efficiently sized, though the terseness borders on under-specification rather than pure concision.

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 zero-param read-only list with annotations covering safety there is no output schema, so the description could have said what a unit contains or whether the list is complete/paginated. It is minimally adequate but leaves that gap.

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 tool takes zero parameters, so the baseline of 4 applies; the description correctly implies an unfiltered full listing with no arguments to supply.

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?

Names the resource precisely and disambiguates jargon by equating 'units' with 'branches', but it is a bare noun phrase with no verb and never mentions the sibling create_gym_unit, so an agent infers 'list' only from the tool name.

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?

No indication of when to call this versus alternatives, no prerequisites, no mention of what to do with the returned units (e.g. passing an id to another tool). Usage must be inferred entirely from the name and annotations.

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