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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the read-modify-write relationship with update_agent_config and the whole-prompt replacement semantics. It does not cover auth or rate limits, which keeps it off a 5.

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, front-loaded with the resource and its fields, then the decisive guidance. The field enumeration is long but each item is meaningful for an editing workflow; a little could be trimmed without loss.

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?

An output schema exists, so return values need no explanation, and the schema carries parameter detail at 100% coverage. What remains for the description to supply, purpose, prerequisite, and the prompt-replacement hazard, is fully present.

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 description coverage is 100% and both parameters (agent_id from list_agents, business_id needed only for multi-business agents) are documented in the schema. The description adds only an incidental note that voice carries a list_voices id, so baseline 3 applies.

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?

States a specific verb ('Read') and resource ('an agent's settings') and enumerates exactly which settings come back (inbound/outbound/text prompts, greeting, voice, model, call length, transfer, summary and lead-score instructions). It is clearly separable from the sibling update_agent_config, which it names explicitly.

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?

Gives an explicit when-to-use rule ('Read this before update_agent_config') and states the reason plus the hazard: inbound_prompt on the update tool replaces the whole prompt, so the text returned here must be edited. This is exactly the kind of prerequisite routing an agent otherwise gets wrong.

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