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

Adds real context beyond the annotations: the pending deliveries are cancelled (the concrete meaning of destructiveHint=true) and a specific permission scope is required. It stops short of saying what happens when no active webhook exists or whether the disable is reversible.

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 compact sentences, front-loaded with the action and effect, then prerequisites and parameter meaning. No filler.

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 one-optional-parameter mutation tool with annotations already declaring destructive and idempotent behavior, this covers effect, permission, and parameter scope. Missing only edge-case behavior (no active webhook, default project resolution).

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 0% and the schema only supplies a UUID format, so the description's 'optional projectId selects an owned OAuth account project' is the only source of meaning for the parameter. It compensates well, though it doesn't say what happens if projectId is omitted.

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 ('Disables an authorized project's active webhook') plus the concrete side effect 'cancels pending deliveries'. It is clearly distinct from configure_webhook in intent, though it never names the sibling explicitly as the enable-path alternative.

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?

Gives a precondition ('Requires handoffs:write permission') and explains when projectId applies, but offers no explicit when-not guidance or direct reference to configure_webhook as the inverse operation. Usage is implied rather than spelled out.

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