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

Annotations already establish read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds useful behavioral context beyond the annotations: it says the result explains why people look at the pattern, how it is computed, what it cannot tell you, and its largest results. It does not cover auth or rate limits, but it meaningfully describes the tool's informational scope.

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 identifies the operation, then a colon-delimited list efficiently previews the returned content. There is no wasted wording, and the key routing information appears first.

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 one-parameter read tool with full schema coverage and annotations covering safety, the description supplies the missing context: what the returned pattern details include. No output schema exists, so the description appropriately previews the return content and limitations.

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 coverage is 100%, so the baseline is 3. The description adds value by stating that the id comes from list_flags, which tells the agent where to obtain a valid id beyond the schema's example ('no-competition').

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?

States a specific verb and resource: 'Get one pattern by id.' It also distinguishes itself from the sibling list_flags by naming the id source and contrasting one pattern with the list operation. An agent can tell immediately what the tool returns and how it differs from list_flags.

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 parenthetical '(from list_flags)' clearly signals that this tool is used after finding an id via list_flags. It does not spell out an explicit when-not-to-use rule, but the alternative and prerequisite are clear enough for correct routing.

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