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

Annotations only declare readOnlyHint=true; the description adds the meaningful behavioral fact that this returns names only and never secret values, which tells the agent it can call this without exposing sensitive material. It does not cover vault configuration, permissions, or ordering, but for a zero-parameter read that is a minor gap.

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, zero filler. The core purpose leads and the get_secret routing follows immediately, so the most important information is front-loaded.

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 zero-param, read-only listing tool with annotations covering the safety profile, the description supplies everything needed to call it: what it returns and where to go for values. Only minor operational details (vault availability, any auth expectations) are absent.

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 no parameters and the schema is an empty object, so there is nothing for the description to disambiguate. Baseline 4 applies; the description correctly adds no redundant parameter talk.

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 ("List secret names in the ops vault") plus the scope limit that only names, not values, are returned. It also names the sibling get_secret as the tool for values, so an agent can distinguish the two 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?

The second sentence explicitly routes the agent: if you need values, use get_secret instead. That is a concrete alternative with a selecting condition, though there is no explicit statement of when not to use this tool or any prerequisite/auth context.

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