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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds meaningful context beyond that: it performs no download and no charge, and it evaluates entitlement logic (one-time purchase vs. PRO remaining monthly downloads). It does not describe the response shape, which limits it to a 4.

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 tightly written sentences with zero filler. The core purpose is front-loaded, and the usage instruction follows naturally.

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?

With no output schema, the description gives a strong conceptual picture of what is checked (purchase status, PRO quota) without explaining the exact return format (e.g., boolean plus reason or remaining count). For the agent's decision about whether to offer a download, this is largely sufficient, though a hint at the return shape would complete it.

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% – both cvId and locale are fully documented in the schema, including the enum and default behavior. The description adds no parameter-specific detail beyond what the schema provides, so the baseline of 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 and resource ('Check whether the user can download a CV') and scopes it precisely to entitlement checks (one-time purchase or PRO remaining downloads). The closing line distinguishes it from an actual download action, setting it apart from siblings like get_takemeup_download_link.

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?

Explicitly says when to call it: 'Use before offering a PDF or Word download.' This gives clear context for invocation. It does not name the alternative download tool by name or state exclusions, so it falls just short of the 5 level.

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