Validate subscription fields

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true; 'WRITE-ish' is consistent with that, not contradictory. The description adds one genuinely useful fact — it does not provision — but says nothing about what happens on invalid input, whether it is idempotent, or what it 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 short clauses, front-loaded, with zero filler. It is arguably under-specified rather than verbose, but nothing is wasted.

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 validation tool with no output schema, the agent has no idea whether success returns a boolean, an error list, or throws — a significant omission. The 'does not provision' boundary is helpful but does not close that gap.

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?

One parameter with 100% schema description coverage, so the baseline is 3. However, the schema is a free-form object (additionalProperties: {}), so the description could usefully have said what fields a valid subscriptionAccount must contain — it does not, leaving the payload shape opaque.

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 (validate) and resource (subscriptionAccount) and explicitly bounds the effect with 'Does not provision', which separates it from create_subscription in the sibling list. The 'WRITE-ish' prefix and 'ValidateFields' internal name add noise rather than clarity.

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?

'validates subscriptionAccount before create' implies the correct call site (pre-flight to create_subscription), and 'Does not provision' rules out the obvious wrong expectation. No explicit statement of when NOT to use it versus create_subscription directly, but the sequencing is clear.

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