set_webhook

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

Annotations only declare mutating, idempotent, non-destructive. The description goes well beyond: storage path (~/.local/share/signal-mcp/webhook.json), that the receiver reads it only at startup, that SIGNAL_MCP_WEBHOOK overrides it, the exact JSON payload shape, and the two possible return objects.

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?

Front-loads the core action, then layers clearing semantics, storage/lifecycle, override behavior, payload and return shape. Dense but every sentence carries operational information; the payload field list is the only slightly expendable element.

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?

No output schema exists, yet the description spells out both return objects, the file it writes, the restart requirement, and the env-var override — everything needed to call it correctly and interpret the result.

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 the baseline is 3, but the description adds meaning the schema lacks: that an empty string (not just null/omission) also clears the webhook, plus the concrete localhost URL format used by the receiver.

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: saving or clearing the webhook URL that signal-mcp's background receiver POSTs messages to. It names the sibling (get_webhook) that retrieves rather than mutates, so an agent can separate the two without opening a schema.

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 covers both branches: provide a URL to set, omit/null/empty to clear, and use get_webhook to inspect the effective value. It also names the operational precondition (restart the service for the change to apply).

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