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

With no annotations, the description carries the full burden. It discloses a behavioral requirement ('Requires a key') and hints at output content ('with the date last seen'). However, it does not explicitly state that the operation is read-only or mention any rate limits or output size limitations. This is adequate for a simple lookup but not rich.

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 is a single, concise sentence that states the core purpose and the key requirement. It is front-loaded with the main content and contains no redundant or filler text. Every word adds value.

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 tool with no parameters and no output schema, the description covers the essential aspects: what data is returned (withdrawn models and their last-seen date) and the access requirement. It could improve by explicitly noting the output format or contrasting with similar sibling tools, but the low complexity makes this adequate.

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?

There are zero parameters, so the baseline is 4. The description adds no parameter-specific semantics (there are none), but it does define what the tool returns, which indirectly clarifies that no input parameters are needed. The schema coverage is 100% (empty properties), so no gap exists.

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 identifies the resource as models no longer in the catalogue and specifies that the date last seen is included. It lacks an explicit verb like 'lists' or 'returns,' but the intent is unambiguous. It also distinguishes from the sibling 'withdrawn_but_installed' by focusing on catalogue status rather than local installation.

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 provides no guidance on when to use this tool versus alternatives such as 'withdrawn_but_installed' or 'find_model.' The only additional information is the requirement for a key, which is a prerequisite rather than a usage direction.

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