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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the danger profile is largely pre-supplied. The description reinforces this with "sensitive write operation; requires confirm=true," adding the confirmation gate, but it does not explain what an update overwrites, how partial updates behave, or what happens to omitted fields.

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, front-loaded with the action and endpoint before the caveat. No filler or repetition, though the endpoint path adds little for an agent that already has the tool binding.

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 non-idempotent, destructive mutation with 10 parameters and no output schema, the description is only minimally sufficient: it covers the confirmation requirement but not which fields are updatable, whether updates are merge or replace, or the effect on policy membership. Annotations carry the safety story, so the gap is not severe, but the description could say considerably more.

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?

With 10 parameters and only 60% schema description coverage, the description should compensate, yet it only references policy_id (implicitly, via the URL path) and confirm. The complex anyOf "users" parameter, whose array-of-objects vs array-of-IDs vs string forms imply different membership semantics, is left entirely unexplained.

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 and resource ("Updates a time off policy") plus the exact REST path, which clearly distinguishes it from create_timeoff_policy, get_timeoff_policy, and list_timeoff_policies. It stops short of explicitly naming those siblings, but the verb+resource pair is unambiguous.

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?

It gives one concrete precondition ("requires confirm=true") and flags the operation as sensitive, which tells the agent when the call will be rejected. However, it offers no guidance on when to pick this over other policy or timeoff mutation tools, nor any prerequisites such as permissions or workspace scoping.

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