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

No annotations exist, so the description carries the full load and does substantial work: it declares that the live session TS is authoritative ('do not repost GeoJSON'), describes the in-band clarification path for modern clients versus CLARIFICATION_REQUIRED for legacy hosts, and warns the agent to compare the derived TAL and inspect disruption_summary next. It does not state what the split mutates/destroys in the existing alignment or any permission requirements, which keeps it short of 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-loaded with a labeled structure (When / Prerequisites / Headless / Distinct / Next / Scenarios) and no filler sentences, though the extremely dense domain jargon and abbreviation stacking (TAL, MC, TS, SP-001..004) make it harder to parse than a plainer two-sentence statement.

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 16-parameter mutation tool with zero annotation coverage, the description covers the workflow and mode-selection well, and an output schema exists so return values need no prose. However, the majority of undocumented parameters and the absence of any statement about what the split changes or requires leave real gaps for an agent to fill by guessing.

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 0% across 16 parameters with no enums, so the description must compensate. It does explain the key args (map_session_id, source_tal_id, target_territory_id, ts_handle/ts, dwell time) and the MC-vs-headless choice, but roughly half the parameters (repair_policy, balance_tolerance, disruption_weight, part_layer, point_layer, label fields, guidance_handle, visit_frequency_field, objective) get no meaning, format, or default guidance.

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 ('split one oversized territory') with an explicit scope qualifier ('minimal disruption to the rest of the alignment'), and explicitly distinguishes itself from the nearest sibling: 'Distinct from auto_build Scoped Split (balanced-from-scratch).' An agent can pick this over auto_build/territory_rebalance without opening a 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 an explicit When clause, prerequisites ('existing TAL with target territory; viewer connected for MC-first'), the two invocation modes (Open MC preferred args vs headless ts_handle/Compact/GeoJSON ts), and a named alternative with the condition that separates them. Scenarios SP-001..004 and a Next step point the agent onward.

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