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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds genuine context beyond that: the enumeration of how a card was earned, the meaning of milestones, and the explicit note that the list holds only earned items with no total or progress counter.

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?

Front-loaded with the core action, then supporting detail on card contents and milestone semantics. The milestone sentence is slightly discursive but earns its place by clarifying what counts as a card. No filler or repetition.

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?

An output schema exists, so return-value shape need not be described, and the tool is zero-parameter and read-only. The description covers purpose, entry contents, and the absence of a progress counter; only sibling disambiguation is missing, which keeps it short of a 5.

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?

The tool takes zero parameters (schema coverage 100%, empty properties object), so the baseline is 4. The 'Args: {}' note simply confirms the no-argument contract, and there is no parameter meaning left to add.

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+resource ('Get the career cards this user has collected') and details what each entry contains: what, when earned, and how (deck | loader | agent | milestone | import). It does not explicitly name or rule out the nearest siblings such as get_user_stats or get_career_memory, so an agent must infer the boundary, but the resource itself is unambiguous.

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 the resource but no when-to-use or when-not-to-use guidance is given and no alternative sibling is named. The line 'There is no total to collect and no progress counter' weakly steers the agent away from a stats-style tool, which is the only routing signal present.

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