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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, covering the safety profile. The description adds valuable specifics about what is returned ('key names, prefixes, and creation dates (not the full key)'), which is genuinely useful for a secrets-adjacent tool. It doesn't address auth/permission requirements or pagination behavior, so it clears the lowered bar but doesn't exceed it.

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 compact sentences, front-loaded with the action and scope, then the return-content clarification. Every clause earns its place with no filler.

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 simple single-optional-param read tool whose annotations cover safety, the description is close to complete. The one meaningful gap is that it doesn't mention pagination/limit semantics or who can list keys, which would help for an openWorld read.

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?

Only one optional parameter (limit) with 100% schema description coverage. The schema already documents it fully; the description adds nothing about the parameter, so baseline 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?

Specific verb+resource ('List all API keys for your Xyle account') with a clear scope qualifier. An agent can distinguish this from create_api_key and revoke_api_key among the many siblings without opening a 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?

Implied usage (read-only enumeration of keys) but no explicit when-to-use/when-not guidance and no alternatives named. Adequate minimum but leaves the agent to infer context relative to api_access or create_api_key.

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