set_webhook

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

With no annotations provided, the description carries full behavioral disclosure. It explains the delivery mechanism (POST), the trigger (every incoming Signal message), the payload structure (JSON fields listed), the disabling behavior (null), and the persistence side effect (saved to disk, survives restarts). This is rich, non-obvious behavioral detail beyond the schema.

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?

Three dense sentences deliver the purpose, payload, use cases, disabling mechanism, and persistence without wasted words. The core behavior is front-loaded; every sentence earns its place.

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 single-optional-parameter tool, this description is complete: it tells the agent what the URL is for, how the endpoint is invoked, what the payload contains, how to clear the webhook, and that the configuration persists. Nothing needed for correct invocation is missing.

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%, so the baseline is 3. The schema already documents 'url' and the clearing behavior ('Omit or pass null'). The description adds an example destination and relation to Signal, but does not materially extend the meaning of the parameter beyond what the schema provides.

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 states a specific verb ('Configure') and resource ('a webhook URL') and clearly defines the behavior: receiving a POST for every incoming Signal message. It distinguishes itself naturally from siblings like get_webhook by describing configuration rather than retrieval.

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 gives explicit usage context: 'Use this to connect signal-mcp to n8n, Make, Home Assistant, or any local HTTP endpoint' and explains the disabling case with 'Pass url=null'. It does not explicitly name alternatives or exclusions, but the context is clear enough for an agent to know when this tool applies.

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