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

Annotations already declare this as read-only, idempotent, non-destructive, and closed-world. The description adds useful behavioral context: it returns groups and path templates, and omitting the group lists every group.

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 short, front-loaded with the read-only nature, and contains no filler. Each clause carries useful information about output content, filtering behavior, or downstream usage.

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 one-parameter read tool with no output schema, the description provides enough context: what is returned, how the optional group changes behavior, and how slug-enabled groups relate to purging. The only mild gap is the vague or potentially mismatched reference to purge_nginx_cache_group.

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 carry parameter meaning. It explains that `group` is optional and that omitting it lists all groups, but it does not clarify what a group value looks like or how it maps to group names, IDs, or slugs.

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 states a specific read operation over cache purge groups and their path templates, and clarifies that omitting a group lists all groups. It is clear what the tool returns, though it does not explicitly compare itself against nearby list or purge tools.

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 implies usage by explaining that a group filters results and that slug-enabled groups can feed a purge workflow. However, it does not explicitly say when to use this tool versus alternatives such as list_cache_flush or purge_cache_group.

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