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

Description details behavioral traits beyond annotations: 'no report generated, no team run, no message sent, no inbox write'. This complements the readOnlyHint and idempotentHint annotations with concrete side-effect guarantees. No contradiction with 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?

Three sentences, each earning its place: purpose, usage context, parameter guidance. Front-loaded with key action and constraint. No wasted words.

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?

Tool complexity is low (2 parameters, 1 required), but description covers purpose, usage, parameter semantics, and behavioral transparency. Output schema exists, so return value explanation is unnecessary. Complete for effective agent invocation.

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%, but description adds significant meaning: explains sample_payload_override is 'Merged over the built-in synthetic payload for this rule's trigger_type — lets you test a specific value.' This clarifies behavior beyond the schema's description. Provides usage context for both parameters.

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?

Description clearly states 'Dry-run a rule's condition_expr against a SYNTHETIC trigger payload — reports whether it WOULD have fired, but NEVER dispatches the action'. The verb (dry-run), resource (rule), and scope (condition test) are explicit. No sibling tool named test_rule, so no ambiguity.

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?

Explicitly recommends use 'immediately after create_rule to sanity-check the condition before it starts evaluating against real events.' It also clarifies what the tool does NOT do (no action dispatch), providing clear when-to and when-not-to guidance.

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