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

Beyond the annotations, the description discloses critical security behavior: values are stored encrypted, list shows names only, delete removes one, and values can never be read back by anyone. This is exactly the kind of write-only, destructive, non-retrievable behavior an agent must understand before invoking.

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 well-structured sentences: the first covers use case and per-action behavior, the second front-loads the irreversible write-only constraint and the alternative tool. Every phrase earns its place.

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?

Given the annotations already cover safety hints, the input schema is fully described, and an output schema exists, the description supplies the remaining crucial context: write-only encrypted storage, no read-back, and the correct sibling for using the secrets. Nothing essential is missing for correct invocation.

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 baseline is 3. The description adds actionable meaning beyond the schema by clarifying that set stores encrypted values, list returns names only, and delete removes a single secret. It still does not discuss individual parameter constraints, but those are fully documented in 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?

The description names the resource (API keys/secrets), the actions (set, list, delete), and the purpose (site needs an API key for weather, CRM, maps). It also distinguishes itself from manage_connections by stating that stored values can never be read back and must be used through connections 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?

It gives a clear when-to-use trigger ('when the site needs an API key') and explicitly routes key usage to the sibling tool manage_connections. The three actions and their effects are also described, so an agent knows which action to choose.

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