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

Annotations declare non-read-only, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful propagation semantics beyond that: future emails and runs hitting a Wait until step pick up the new value, while already-waiting runs keep the previously read value. It stops short of covering how automation steps other than Wait until behave or what a partial update returns.

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 front-loaded sentences with no filler; the propagation clause earns its place. Minor issue: 'keep the date they read' reads as date-type-specific even though the sentence is written generally, which slightly muddies the framing.

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 6-parameter mutation with low schema coverage and no output schema, the description covers side effects well but leaves parameter behavior, partial-update semantics, and error conditions unaddressed. Adequate but with clear gaps an agent would hit on first call.

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 description coverage is only 33% and the description says nothing about the 6 parameters — not id vs key semantics, not that partial updates are allowed, not type/value coupling, not what a null value means. The 'date' wording hints at date-type value behavior but is not framed as parameter guidance, so it does not compensate for the coverage gap.

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 clear verb+resource ('Change a global value') that is unambiguous against siblings like create-global-value and delete-global-value, whose verbs already differentiate them. It does not explicitly call out the distinction, but the purpose is specific.

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?

No guidance on when to use this versus create-global-value (new value) or delete-global-value (removal), and no mention of prerequisites such as needing an existing ID/key. Usage is only implied by the verb 'change'.

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