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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. Beyond that, the description adds valuable context: the tool returns metadata and env var keys, and that values are never exposed — a security guarantee an agent needs before trusting the tool's output.

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 sentences with zero filler. The verb+resource is front-loaded, and the second sentence earns its place by disclosing both return contents and a critical security property.

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 one-parameter get-by-id tool with no output schema, the description covers the return shape but omits error/not-found behavior, id provenance, and any differentiation from similarly named read tools like getCredential. Adequate but with clear gaps.

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 description coverage is 0%, so the description must compensate. It confirms lookup is 'by id,' but adds nothing about what an env-var secret id is, how to obtain it (e.g., via listSecrets), or what the uuid parameter semantically refers to beyond the schema's format constraints.

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: 'Get an env-var secret by id.' The qualifier 'env-var secret' distinguishes it from sibling tools like getCredential and getConnection, though it doesn't name them explicitly. The second sentence sharpens scope by defining exactly what is returned.

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 implies when to use the tool (when you need secret metadata or env var keys) but gives no explicit selection criteria, no exclusions, and names no alternatives. The 'secret values are never exposed' line is more a behavioral constraint than routing guidance.

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