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

No annotations are provided, so the description carries the full disclosure burden. It implies a read-only, non-destructive listing and defines the semantics of the result set (models newly entered the register), but says nothing about ordering, pagination behavior, or what a record contains.

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 short sentences: the definition of the result set comes first, the use cases second. No filler, no repetition of schema content, and it stays front-loaded.

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 two-optional-parameter listing tool with no output schema, the description plus schema is enough to invoke it correctly. The remaining gap is return-format/ordering, which the description could reasonably have mentioned given there is no output schema and no annotations.

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 description coverage is 100%, so both parameters (days, limit) and their defaults are already documented in the schema. The description's phrase 'within the last N days' merely echoes the days parameter and adds no format, bounds, or interaction detail (e.g., how limit interacts with days). Baseline 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 resource (models) and a precise selection criterion (first recorded in the register within the last N days), which is more than a restatement of the name. It does not explicitly name or contrast with siblings like search_models, so an agent must infer that this is a recency-scoped listing rather than a keyword search.

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?

Provides concrete triggering questions ('what shipped recently', 'what is new in open-weight models'), which tells the agent the intended query shape. It stops short of stating when NOT to use it or naming search_models as the alternative for filtered/keyword lookups.

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