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

Annotations already declare read-only, idempotent, non-destructive, so safety is covered. The description adds value beyond them: results are limited to *active* commissions, and the data-sources note warns that returned ids are internal lookup values, not citable documents — a real behavioral constraint an agent would otherwise get wrong.

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?

Purpose and primary use are front-loaded in the first two sentences; examples are inline rather than listified. The closing data-sources paragraph is longer than strictly needed but carries the non-citability caveat that would otherwise be lost.

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?

Output schema exists, so return values need no explanation, and the description covers scope, filtering, and the intended downstream use. Nothing essential is missing for a simple lookup tool; only minor edge cases (pagination, empty results) are unaddressed.

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 100%, so the baseline is 3. The description still adds the default when country_code is omitted ('all accessible countries') and restates the comma-separated format with examples plus acronym matching, which sharpens how `q` behaves beyond the schema's wording.

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 and resource ('Returns active congressional commissions') and immediately ties it to a downstream consumer ('discover commission_id values to pass to list_bills'). That routing sentence separates it cleanly from sibling list_* lookup tools.

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?

Explicitly names the primary use case and the sibling it feeds. It also gives the fallback behavior ('omit for all accessible countries') and concrete filter examples, so the agent knows both when to call it and how to call it with no configuration.

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