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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false. The description adds a genuine behavioral detail beyond that: the key value itself is never returned, and it names the underlying endpoint (GET /validate), which tells the agent this doubles as a credential-validation read.

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 with the primary payload front-loaded and no filler. Even the endpoint reference earns its place by clarifying what the call actually does.

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?

No output schema exists, but the description compensates by naming the returned fields and stating what is withheld. For a no-parameter read tool this is nearly sufficient, with only minor gaps such as error/expiry-state behavior.

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?

The tool takes zero parameters, so the baseline is 4. The description introduces no parameter syntax or constraints, which is appropriate since there is nothing to pass.

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 and resource ('Details of the Kinsta API key in use') and enumerates the returned fields (name, status, expiry, company id). It is unambiguous and distinct from sibling list/get tools, though it does not explicitly name which sibling to use instead.

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?

Usage is implied rather than stated: a reader infers this is for validating/identifying the credential currently in use. There is no explicit 'use when...' or 'not for...' guidance and no named alternative, but the narrow scope makes the intent reasonably clear.

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