Received webhook events

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

Annotations already declare readOnlyHint=true, idempotentHint=true, covering safety and idempotency. Description adds behavioral insight: reads an in-process buffer, does not call Avito API, does not mark anything as read. This context enhances understanding beyond annotations. No contradiction.

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 purpose, followed by behavioral note, prerequisites, and filter options. Every sentence is essential; no redundant information. Efficient and well-structured.

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?

Despite no output schema, the description sufficiently explains what is returned (events, newest-first) and covers dependencies (prerequisites). For a read-only tool with comprehensive annotations, this is complete enough for an agent to use correctly.

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%, so parameters are fully described in the schema. Description briefly mentions filtering options ('Supports filtering by chat_id, a `since` cutoff (ISO-8601 timestamp or epoch seconds/ms), and a `limit`'), but this largely restates the schema. Baseline 3 is appropriate.

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 'Returns Avito messenger webhook events RECEIVED by this server (new chat messages), newest-first.' It specifies the verb (returns), resource (webhook events), and scope (received, not from API). Distinguishes from sibling tools like messenger_get_webhook_status (config/stats) and messenger_register_webhook (subscription).

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 states when to use: to get received events without calling the API. Provides prerequisites: 'Requires the receiver to be enabled (set AVITO_MCP_WEBHOOK_SECRET) and Avito subscribed to the receiver URL (messenger_register_webhook).' Mentions alternatives: messenger_register_webhook for subscription, messenger_get_webhook_status for config check.

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