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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered; the description adds genuinely new operational context — a 2-credit cost, availability on every plan, and the precise 1 August–31 July season window. It does not mention rate limits or result-set size, which would be the next layer.

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 its metrics, then the lookup trick, then cost/availability. 'Costs 2 credits. Every plan.' delivers two facts in six words with no waste.

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?

An output schema exists, so return shapes need not be described. With cost, plan eligibility, season boundaries and name-lookup behavior all stated, an agent has what it needs to call correctly; only ordering/limits and the meaning of 'scope' are left implicit.

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 only 25%, and three of four params are enums with no per-value documentation. The description compensates well: it defines the season window, explains the national-vs-state axis, and — most valuably — reveals that supplying 'name' changes the query into a cross-table lookup. Scope's individual values (metro/provincial/country/picnic) remain undocumented in prose, but the enum names are largely self-describing.

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 ('Racing Australia jockey premiership tables') and enumerates the metrics returned: wins, placings, prize money, strike rate. The domain qualifier 'jockey' cleanly separates it from trainer_stats and greyhound_stats in the sibling list.

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?

Tells the agent exactly how to enter lookup mode ('Give name to find one jockey across every table') and constrains season and geography (current/previous, national or state scope). It stops short of when-not guidance or naming a sibling alternative, which keeps it at 4 rather than 5.

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