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

The annotations already declare 'readOnlyHint: true', indicating no modifications. The description reinforces this with 'check'. It adds the nuance that it applies to the 'most recent order', but does not disclose additional behavioral aspects such as response format, error states, or rate limits. With the annotation covering safety, the description's extra context is minimal.

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 description consists of two short sentences, each conveying essential information without redundancy. It is front-loaded with the core purpose and immediately follows with the prerequisite. Every word earns its place, making it highly efficient.

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?

Given the simple nature of the tool (one required parameter, no output schema, read-only action), the description is functional but lacks completeness. It does not explain what the status check returns (e.g., a string value, object, success/failure) or how to interpret results. It also does not clarify what happens if there is no 'most recent order' (e.g., error condition). Additional context would improve agent decision-making.

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 input schema has 100% description coverage for the single parameter 'session_key'. The description's phrase 'session key from a previous tool call' aligns exactly with the schema description, providing no additional semantic details beyond what is already in the schema. Thus it meets the baseline without adding extra value.

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 clearly states the action ('Check the status') and the specific resource ('the most recent order'). It is distinct from sibling tools like 'create_order' or 'check_data_balance', which focus on different resources or actions. The use of 'most recent' adds a precise scope.

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 mentions a prerequisite ('Requires a session key from a previous tool call'), which provides some guidance on when to use it. However, it does not explicitly state when to use this tool versus alternatives like 'check_data_balance' or 'search_packages', nor does it specify what type of previous tool call is expected. No exclusion or alternative guidance is given.

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