List block patterns

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

The description discloses a key behavioral detail beyond the annotations: pattern content is omitted by default because it is large, and include_content returns truncated markup. This complements the readOnlyHint and destructiveHint annotations with useful operational context.

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 focused sentences deliver the most decision-relevant information: scope, sources, filtering, and the content-size trade-off. There is no filler, and the key facts are front-loaded.

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 tool with a fully documented schema, the description covers sources, filtering, and the important include_content behavior. It does not mention pagination or result shape, but those are less critical given the readOnlyHint annotation and the absence of an output schema.

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 input schema covers all 7 parameters with 100% description coverage, so the description does not need to re-explain them. It adds mild context around sources and the include_content default, but it does not significantly extend parameter meaning beyond what the schema already provides.

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 uses a specific verb and resource ('List the block patterns registered on the site'), enumerates the sources (core, theme, plugins, pattern directory), and mentions categories and filtering. This clearly distinguishes it from sibling tools like list_block_types and list_reusable_blocks.

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?

It gives a concrete use case: reuse an existing pattern's markup instead of hand-writing layout. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for an agent to select it appropriately.

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