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

With no annotations, the description carries the burden of behavioral disclosure. It does add useful context: the endpoint is GET, it lists regular and special sessions, and the corpus is 2026-forward only. However, it does not mention pagination behavior, ordering, response format, or any access constraints, which a fully transparent description would include.

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 focused sentences with no fluff. The endpoint is front-loaded, the returned fields are listed, use cases are given, and the coverage limitation is stated. Every sentence contributes.

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 optional-parameter list tool, the description covers the important operational knowledge: what the tool returns, when to use it, what omitting state does, and the corpus boundary. It does not describe ordering or pagination, but the input schema handles max_items defaults, so nothing critical is missing for correct invocation.

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 the baseline is 3. The description adds some context about state ('Omit state to list every jurisdiction's sessions') but does not add meaningful semantics beyond the schema, which already explains state format and max_items behavior.

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 description names a specific verb and resource ('List legislative sessions') and immediately specifies what the payload contains: regular/special sessions, years, dates, and session_id. It is clearly distinct from the sibling tools, which are mostly get_* operations for individual bills, legislators, or session statistics.

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?

The description gives explicit use cases: resolve a bill's session, find the current session for a state, and obtain session_id for search_bills filtering. It also explains the scope-changing behavior ('Omit state to list every jurisdiction's sessions'). It does not mention when not to use it or name alternatives, but no close alternative exists among the siblings, so this is a minor gap.

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