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

The description adds valuable behavioral context beyond annotations: it discloses the synchronization side-effect and the idempotent no-op behavior for identical rules. These align with the idempotentHint annotation and enrich the destructiveHint, which alone would not convey the external dictionary sync or idempotency details.

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 extremely concise and front-loaded with the core action. The second sentence adds a critical behavioral note without waste. Every word contributes to understanding the tool's purpose and side effects.

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 complexity of a mutation tool with annotations and an output schema, the description covers the essential aspects: the operation, synchronization, and idempotency. It does not explain return values, but the output schema exists. Minor gaps like error handling or prerequisites are acceptable given the schema and annotations.

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?

All four parameters are fully described in the input schema (100% coverage), so the description does not need to add much. It adds the context that a rule is identified by word (implied by 'add or replace'), but this is minor. The baseline of 3 is appropriate because the schema carries the parameter details.

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's action: add or replace a pronunciation rule, and mentions synchronization with the ElevenLabs dictionary. It distinguishes itself from the sibling remove_pronunciation_rule implicitly by focusing on add/replace, but does not explicitly name alternatives, so it is not a 5.

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 does not provide explicit guidance on when to use this tool versus the sibling remove_pronunciation_rule or other tools. It implies usage for adding or replacing rules, but no explicit exclusions or alternatives are mentioned, leaving the agent to infer based on tool names alone.

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