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

Annotations declare readOnlyHint=false, openWorldHint=true, destructiveHint=false. The description adds meaningful context beyond those: it requires explicit user intent, signs only the exact bound event, and 'never publishes'. It doesn't cover failure modes or what the signer returns, but the safety-relevant behavior is well disclosed.

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?

Two short sentences, tightly front-loaded with the action and the key constraints ('explicit user intent', 'never publishes'). 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 signing operation it covers the safety-critical points (user intent required, no publish), but omits the relationship to prepare_event, what the signer approval flow looks like, and what happens on rejection. No output schema exists, so some return-shape context would have helped.

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 50%; confirm_signature is documented in schema but intent_id has no schema description. The description implies intent_id refers to 'a fresh intent' but adds no format, provenance, or lifecycle detail beyond what the schema already conveys for the boolean.

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?

Clear verb ('sign') and resource ('the exact event bound to a fresh intent'), distinguishing it from siblings like prepare_event and publish_event. However, it doesn't explicitly name where the event comes from (presumably prepare_event) or how it differs from approve_grynvault_browser_handoff, leaving some differentiation to inference.

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?

Implies usage requires 'explicit user intent' and a fresh intent, but doesn't state when to call this vs prepare_event first, or vs publish_event. No explicit preconditions chain is given, so an agent must infer the workflow.

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