Update key

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=true), so the bar is lower. The description adds real behavioral value the annotations cannot: field support varies by key type and the API will reject out-of-type fields, preventing a failed call. It stops short of describing reversibility or response behavior.

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 dense sentences, front-loaded with the core action, then the conditional field matrix, then the failure-mode warning. No filler and each sentence carries distinct information.

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 an 8-parameter mutation tool with a nested object and no output schema, the description covers the key risk (wrong fields for the key type) and lets the schema carry per-parameter formats. Minor gap: nothing about return value shape, though no output schema exists to cover it.

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 100%, so the baseline is 3, but the schema only tags each field with a parenthetical like '(federated only)'. The description consolidates those tags into a coherent key-type-to-field mapping and adds the auth-key rejection rule, which adds meaning beyond the schema.

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 ('Update') and resource ('existing key'), cleanly separating it from create_key, delete_key, and get_key siblings. It does not explicitly name an alternative tool, so it lands at clear-but-not-sibling-differentiating.

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?

Gives explicit conditional guidance keyed on key type — which fields are valid for auth keys, OAuth clients, and federated identities — including a hard when-not: auth keys must receive only 'description' or the API rejects the call. It does not discuss when to reach for this tool over siblings, but the field-eligibility rules are concrete usage instruction.

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