get_webhook

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: the SIGNAL_MCP_WEBHOOK environment variable takes precedence over the stored URL, which directly affects how the returned value should be interpreted. It does not cover error or failure behavior, so it falls short of fully rich disclosure.

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 short sentences with zero filler, and the return shape is front-loaded before the precedence rule and the sibling pointer. Every sentence carries distinct information.

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?

With no output schema, the description supplies the return format ({url} or {url: null}), the precedence rule governing the value, and the routing to the mutating alternative. Nothing an agent needs to call and interpret this correctly 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?

The tool takes zero parameters, which is the baseline-4 case. The description confirms this explicitly ('No parameters.'), matching the empty schema with no ambiguity.

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 and resource ('Return the webhook URL in effect') and even specifies the exact return shape ({url} or {url: null}). It names its counterpart sibling, set_webhook, so an agent can distinguish read from write without opening either 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 names the alternative ('Use set_webhook to change or clear it') and the condition that selects it, plus notes there are no parameters. An agent knows exactly when to call this versus the mutating sibling.

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