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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine value beyond that: it discloses that secret variable values are redacted by the API, which the agent would otherwise only discover from the response.

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, zero padding: the purpose is front-loaded and the redaction caveat follows immediately. Every clause carries information.

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 two-parameter, zero-required read tool with full schema coverage and readOnlyHint, the description covers purpose, scope and the one non-obvious behavioral caveat. Minor gap: no mention of pagination behavior or result ordering, though the schema supplies the paging parameters.

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 100%, so page and limit are already documented in the schema, and the description correctly does not repeat them. It adds no pagination semantics beyond the schema, 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?

States a specific verb (List) and resource (account-level environment variables), with the scope qualifier 'account-level' narrowing it. It does not name a sibling to contrast against, but a read/list tool is unambiguous here.

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?

Usage is implied by 'List all account-level environment variables' — the agent can infer this is the read path for variables versus checkly_create_variable. However, there is no explicit when-to-use, no exclusion, and no alternative named.

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