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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description goes beyond them by naming the six aggregate metrics returned, effectively documenting the response shape in the absence of an output schema.

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 compact sentences, front-loaded with the resource and metrics, then usage cue, then prerequisite. No filler or restatement of the title.

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 one-parameter read-only aggregate tool with no output schema, the description supplies both the invocation prerequisite and the returned metrics, leaving no material gap an agent would need filled before calling 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 100% and the single parameter's schema description already says 'session_id from list_sessions (filter by state)', so the description's identical guidance adds no new syntax or format detail. Baseline 3 is appropriate when the schema fully carries parameter meaning.

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 ('Headline counts for one legislative session') and enumerates the exact metrics returned (bills filed, passed, signed, vetoed, roll calls, active legislators), plus the endpoint. This makes it clearly distinguishable from narrower siblings like get_session_breakdown or get_session_vote_participation.

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 an explicit entry-point cue ('Start here for "how is the 2026 Florida session going"') and prerequisite routing ('Get session_id from list_sessions'). It lacks an explicit when-not-to-use or named alternative for drill-downs (e.g., get_session_breakdown), which keeps it 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.