⚠️ Register webhook receiver

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

Annotations indicate destructiveHint=true and readOnlyHint=false. The description adds that the subscription is additive (does not delete others) and requires a public HTTPS address. It also states the effect (Avito will POST events) and pairs with read tools. 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?

The description is front-loaded with the main action and uses multiple sentences to cover prerequisites, behavior, and sibling tools. While comprehensive, each sentence adds necessary context. Slightly verbose but efficient overall.

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 webhook registration (public URL requirement, additive behavior, multiple related tools, safety constraints), the description covers all essential aspects: purpose, distinction from similar tool, prerequisites, side effects, and pairing with read tools. No output schema, so no missing return value explanation.

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 the description adds significant value: the url parameter's safety constraint (must equal publicUrl+path+secret), the dryRun preview behavior with default from config, and idempotencyKey's duplicate protection and TTL. This goes well beyond the schema descriptions.

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 specifies the action (subscribes), resource (webhook receiver URL), and outcome (messenger events start flowing). It explicitly distinguishes from sibling tool messenger_post_webhook_v3 by noting the auto-fill behavior, and mentions pairing with messenger_get_webhook_events and messenger_get_webhook_status.

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 explains when to use (to start receiving events), alternatives (messenger_post_webhook_v3 for manual URL), prerequisites (public HTTPS address), and how to unsubscribe (messenger_post_webhook_unsubscribe). Provides clear guidance on when to use this tool vs. others.

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