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

With no annotations, the description carries the full burden and does it well: 'Only what you pass changes' declares partial-update semantics, plus prerequisite ('needs a connected bot'), latency ('~1 min'), and cost model ('free to configure; calls billed per minute'). It omits error behavior for invalid voice_id/locale values and whether changes affect in-flight calls.

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?

Four short sentences, front-loaded with the object being configured, then prerequisite, update semantics, latency and cost. Every clause carries information and nothing repeats the schema.

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?

For a 23-parameter mutation tool with no annotations and no output schema, the description covers the things an agent must know before calling: connected-bot prerequisite, partial vs full update, one-minute propagation, and billing. The remaining gap is disambiguation from set_telegram_voice_calls, which is the highest-risk omission given the names.

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?

At 70% schema coverage the description only adds one concrete field-level note ('the mini app look (visual)') and otherwise delegates via 'the same settings as set_agent_voice'. Roughly seven parameters (volume, denoising_mode, dynamic_voice_speed, ambient_sound_volume, backchannel_frequency, dynamic_responsiveness, interruption_sensitivity) have no description anywhere, and the cross-reference does not fully close that gap.

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+resource ('Voice and behaviour of the Telegram bot's voice calls') and scopes it against the website widget and against set_agent_voice ('same settings as ... plus the mini app look'). It never distinguishes itself from the near-identically-named sibling set_telegram_voice_calls, which is the one alternative an agent is most likely to confuse it with.

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?

'Separate from the website widget' plus 'same settings as set_agent_voice' gives a usable routing rule, and 'Needs a connected bot' states the prerequisite explicitly. It stops short of naming when to prefer set_telegram_voice_calls or reconfigure_telegram_bot, so the boundary against the closest siblings is left to inference.

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