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

Annotations only declare readOnly/non-destructive safety, and the description adds genuinely new behavioral context: the empty-list-vs-error distinction for missing months, no authentication needed, no cost, and a source attribution. It does not describe pagination or result ordering, which are the only meaningful gaps for a read-only lookup.

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?

Four short sentences, front-loaded with the resource definition before the caveats. Classifying the note text and its example in the first sentence is exactly right. The 'Not legal advice' line is defensible for a government-data tool but is the least load-bearing sentence.

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 an output schema present, the description need not explain return shape, and it correctly focuses on the one thing the schema cannot express: the empty-result versus error distinction. Source attribution and access constraints round it out. Nothing critical is missing for a single-parameter read.

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% and the single 'month' parameter is fully documented with format and pattern, so the schema does the heavy lifting. The description adds the failure behavior for an unloaded month, which is useful but is really an outcome rule rather than added semantics on the parameter itself. Baseline 3.

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+scope: the lettered advisory notes published in a given month's Visa Bulletin. The parenthetical example ('EB-1 India may become unavailable') pins down exactly what a 'note' is, and the phrase 'forward-looking text' cleanly separates this tool from get_visa_bulletin, which returns the bulletin's tables.

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?

Clear invocation context is given: free, no sign-in required, and the outcome of an empty month versus a month not on file. It implicitly routes the agent (this is the notes subset, not the full bulletin) but never names a sibling tool or explicitly says when not to use it, so it stops short of a 5.

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