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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds genuinely new behavioral context: the corpus boundary (2026-forward) and the omit-state semantics that change result scope. It stops short of stating pagination/ordering behavior beyond the schema's max_items cap, so not a 5.

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 sentences, each earning its place: resource + returned fields first, then actionable use cases, then the scope caveat. Front-loaded and free of filler; the only nit is the 'sine-die' typo for sine die.

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 list tool with no output schema, everything needed is present: what comes back, when to call it, how to route the result into search_bills, and the temporal limit. Nothing an agent must know to call it correctly is missing.

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, but the description adds meaning the schema does not: omitting `state` switches the call from a state-scoped list to a full multi-jurisdiction list. That is a semantic consequence of a parameter, not a restatement of its type.

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 resource (legislative sessions, GET /v1/sessions) and enumerates exactly what a row contains: year, start/sine-die dates, session_id, and the regular-vs-special distinction. An agent can distinguish this from get_session_breakdown or get_session_dashboard, which are analytics siblings, without opening any schema.

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 three concrete use cases (resolve a bill's session, find the current session for a state, obtain a session_id for search_bills) plus an explicit negative case: omit `state` to list every jurisdiction. The corpus caveat ('2026-forward only') prevents a known failure mode before the call is made.

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