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

Description explicitly states 'Side-effect-free' which aligns with destructiveHint=false. It explains the tool returns the updated list, indicating no mutation of inputs. This adds valuable behavioral context beyond annotations.

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 sentences, no redundant words. Front-loaded with purpose. Every sentence contributes necessary information.

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?

Given the tool has 2 parameters, nested objects, and output schema, the description covers purpose, usage pattern, and side-effect-free behavior. It does not detail output format, but output schema exists. Minor gap: could mention the output is a new list.

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%. Description adds meaning by explaining the role of each parameter: 'constraints' as existing list (omit for empty), 'constraint' as the one to append. Also mentions 'validated' which hints at input validation.

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 verb 'add' and resource 'sketch constraint to a list'. It distinguishes from siblings by specifying the domain (sketch constraint) and the action (appending to a list).

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 gives explicit context: 'Use this when you need to add a sketch constraint to a list.' It also provides usage pattern: 'pass { constraints, constraint } and receive the updated list.' It does not mention when not to use or alternatives, but context is clear.

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