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

With no annotations provided, the description carries the disclosure burden. It adds useful behavioral detail beyond purpose: it includes documents already received and uses a default look-ahead window of 30 days. Since this is a read-only 'List' operation, the lack of explicit side-effect warnings is acceptable, though it could mention sort order or output format for full transparency.

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 entire description is one focused sentence that front-loads the action and resource, adds an important inclusion qualifier, and ends with the purpose. Every phrase earns its place; there is no redundancy or filler.

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 tool with no output schema or annotations, the description is nearly complete: it states what is listed, the default window, the inclusion behavior, and why it is used. Minor gaps like return format or sorting are not critical for an agent to successfully invoke the tool, but a brief mention would make it fully self-contained.

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 schema already describes the 'days' parameter as 'Look-ahead window in days (default 30)' with 100% coverage. The description repeats this default without adding any new meaning, so it contributes no additional parameter value beyond the schema.

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 uses a specific verb ('List') and resource ('vendor documents') with a clear scope ('expiring within the next N days'), and the added clause 'including ones already received' distinguishes it from sibling tools like list_missing_docs and search_vendor_docs. An agent can immediately understand what this tool does and how it differs from similar list/search tools.

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 gives clear context: it is meant for identifying vendor documents that expire soon so renewals can be requested. It does not explicitly mention alternatives or 'when not to use', but the intended scenario is evident and no misleading exclusions are present.

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