List Blocks

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

The description goes beyond the readOnlyHint annotation by disclosing that the output is never truncated, and it explains how the compact envelope always reports truncated=false. This adds valuable behavioral context about completeness and a specific output detail.

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 two sentences, with the primary purpose in the first and a key behavioral note in the second. It is concise, front-loaded, and contains no filler.

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?

The tool is simple with only two parameters, both fully documented in the schema, and an output schema is present. The description covers the essential behavior (listing all blocks, never truncating), making it complete without needing to explain return values.

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 already provides 100% coverage of the two parameters, including descriptions and defaults. The tool description does not add any additional parameter-level meaning beyond what the schema offers, so it stays at the baseline for full schema coverage.

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 all block definitions in the drawing, enumerating specific attributes (name, origin, attribute count, entity count). It is distinct from sibling listing tools by targeting blocks specifically, making the verb+resource combination unmistakable.

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 establishes a clear use case: retrieving all block definitions. However, it does not explicitly mention alternatives or situations where a different tool would be more appropriate, so it lacks the explicit when-not-to-use guidance needed for a 5.

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