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

Beyond the annotations, it discloses real behavioral traits: create-or-update (upsert) semantics, the downstream effect that every interpolating cluster re-renders on its next reconcile, and a hard input rejection rule for secret-like values. It does not mention auth/permission requirements, but it adds substantial context the annotations don't carry.

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 tight sentences with the purpose front-loaded, then the side effect, then the constraint. Every sentence earns its place; no filler or restated name.

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 three-parameter upsert with no output schema and safety annotations already present, the description covers purpose, side effects, and a key input constraint. A note on required permissions or the response shape would make it fully complete, but nothing essential for calling it correctly is missing.

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 100%, so the schema already documents name, value, and description with syntax (the ${{ ankra.variables.<name> }} reference form). The description adds one constraint tied to 'value' (secret-like values refused) but otherwise does not extend parameter meaning, so the baseline of 3 applies.

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 opens with a precise verb+resource: 'Create or update (upsert) an organisation variable.' The scope qualifier 'organisation' implicitly distinguishes it from the sibling set_cluster_variable, so an agent can tell what the tool applies to without opening the schema.

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 clear when-not guidance: secret-looking values are refused, so secrets must go through SOPS instead. It also frames the use case ('plain configuration'). It does not, however, explicitly route the agent between organisation vs cluster variables or env-secret tools, so it stops short of full alternatives coverage.

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