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

Annotations already declare readOnly/idempotent/openWorld, so the bar is lower, yet the description adds real semantic caveats: 'not_recorded means only the source list, never abstention', party totals count non-tellers and tellers separately from headline counts, and detail preserves teller identities. It does not cover error behavior or cross-House mismatch consequences, which keeps it from 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?

Front-loads the search case correctly and has no filler, but it is a single semicolon-chained run-on that packs mode routing, caveats, and cursor rules together, making it harder to parse than a short bulleted structure would be. Terms like 'roster selectors' and 'memberVote' are introduced without explanation.

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 12-parameter, 4-mode tool with an output schema, the description covers mode selection, required divisionId, cursor vs contentCursor distinction, and data-interpretation quirks across all modes. Nothing essential for correct invocation 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 baseline is 3; the description still adds meaning by tying memberId results to memberVote with the recorded lobby and teller flag, clarifying party is an exact source label 'not a party ID', and explaining that divisionId must come from the same House. That is genuine value beyond the schema text.

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 ('Search official Commons or Lords division summaries') and enumerates the four operation modes (search, detail, voters, party_totals). The resource noun (division summaries) implicitly separates it from siblings like search_hansard or search_bills, though no sibling is named explicitly.

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 clear per-mode routing: text/date/member filtering for search, and 'use detail, voters or party_totals with a divisionId from the same House'. Also states the operational rules for cursors ('Follow collection cursors with unchanged filters'). No explicit when-not-to-use or named alternatives among the ukparl_* siblings.

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