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

Annotations already flag a non-read-only, non-idempotent write, and the description adds genuinely new context: one request per call and that the roster is hand-curated, which explains why results are not immediate and why retries aren't idempotent. It omits what the caller gets back or any auth/prerequisite requirements.

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?

Three compact sentences, front-loaded with the purpose followed by the routing condition and operating constraints. Dense but each clause carries weight, though jargon like 'enrolled gridpoint' slightly slows comprehension.

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?

With no output schema, the description should ideally state what a successful request yields; 'curated by hand' implies an asynchronous, non-guaranteed outcome but doesn't confirm it. For a simple one-arg submission tool with annotations covering the safety profile, the coverage is otherwise 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?

Schema description coverage is 100%, so both parameters are already documented in the schema. The description's 'One request per call' is a mild operational constraint but adds no syntax or format detail beyond the schema, so the baseline of 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 verb+resource ('Ask for a city to join the Anecast roster') and spells out what membership grants (daily editions, station history, graded forecast). It also distinguishes itself from the sibling tools by noting they answer by lat/lon for non-roster places, so an agent can pick it without opening schemas.

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?

Gives an explicit trigger condition ('Use when a place is not a roster city') and clarifies the alternative behavior of the other tools for unenrolled places. It stops short of stating a hard exclusion (e.g., don't request a city already on the roster), but the context is clear enough to route correctly.

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