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

With no annotations, the description carries the behavioral burden and provides meaningful details: 404 signals a never-written key and should not be treated as an error, auth.sessionToken is required and forwarded as a Bearer token, and the payload value is decrypted. It does not describe success response shape or other error cases, so it is not a 5, but it is strong for a simple read tool.

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?

The purpose is front-loaded in the first sentence and the description is compact, with the 404 warning clearly bolded. The final preference sentence is slightly tangential to invoking this specific tool but still relevant to integration quality.

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?

The description covers the core invocation details and the notable 404 behavior. However, there is no output schema and no annotation, and the description does not indicate what a successful response looks like or how to handle auth/connection failures; it also says auth.sessionToken is required while the schema marks `auth` itself optional. These gaps leave an agent with reasonable but incomplete guidance.

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 0%, so the description must compensate. It clarifies the `key` parameter as the payload key, explains the `auth.sessionToken` requirement and Bearer forwarding, and advises stable `connection.workspaceName`/`appId` usage. It does not cover `connection.host` or body/query, but the schema itself describes host and body/query are empty.

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 opens with 'Retrieves the decrypted payload value for `key`', which names a specific verb, resource, and the parameter involved. It is clear about what the tool does, but it does not explicitly differentiate this from siblings such as get_sessions or get_sessions_identity, so it misses the top criterion for a 5.

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 description gives no guidance about when to choose this tool over alternatives and never names a sibling. The note about preferring connection.workspaceName/appId is configuration advice, not tool-selection guidance; the 404 note is error handling rather than usage direction.

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