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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the bar is lower, but the description adds genuine operational context: results may be reported under combined reporting units and historical results may be unavailable. Those data-quality caveats affect interpretation of the output and are not derivable from the schema or annotations. It stops short of saying what happens when no results exist or how errors surface.

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?

One compact sentence, front-loaded with the primary payload and ending with the caveats. Nothing is redundant, though the telegraphic noun-phrase style makes it less immediately parseable than a full clause would be.

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 two-parameter read-only lookup with no output schema, the description conveys the data domain and two important caveats, which is close to adequate. Missing is the meaning/origin of the required code and any indication of return shape or granularity (single locality vs. nested breakdowns), leaving the agent to infer how to call it.

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 coverage is only 50%: election_id is well documented in the schema (latest / k26 / full date), but code has no description beyond numeric bounds, and the description adds nothing about what the code identifies or where to obtain it. With a coverage gap this size the description should compensate, and it does not.

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 fragment names the specific payload returned for a locality: votes, parties, blocs, turnout, plus combined reporting units and missing historical results. That content set distinguishes it from siblings like get_election and get_analytics, though the sentence lacks an explicit verb (e.g., 'fetch') and never says it is keyed by locality code.

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?

No when-to-use or when-not-to-use guidance is given, and no alternative is named. In particular, the sibling search_localities exists for resolving a locality name to a code, and the description never points the agent there, nor explains when to prefer this tool over get_analytics or get_election.

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