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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and openWorldHint=false, so safety and determinism are covered. The description adds no operational context beyond the annotations — no information about data source, coverage limits, or latency.

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?

Two sentences: the first states the resource and output statistics, the second front-loads example user queries. No wasted words or jargon.

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?

Output schema exists and annotations cover safety, so the description need not explain return values. It covers the resource, filters, and usage triggers adequately for a no-required-param lookup tool, though it doesn't mention the 5-year trend default or output granularity, which is a minor omission.

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 100%: every one of the six parameters (role, year, sector, board_size, market_cap, include_trend) is documented in the schema with defaults and value hints. The description only hints at the filter dimensions ('by sector, market cap, and role') and adds no syntax or format detail beyond what the schema provides, so baseline 3 applies.

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: 'Get NZX director compensation benchmarks — median, P25/P75 board fees by sector, market cap, and role.' Distinguishes itself from sibling 'get_compensation_benchmark' and 'get_executive_compensation' by specifying director fees and the NZX scope, so an agent can select it without opening schemas.

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?

Provides explicit trigger phrases ('what does a chair earn?', 'director fee benchmarks', 'compensation comparison') that map natural-language user queries to this tool. It does not, however, name or exclude the closest alternatives like 'get_compensation_benchmark' or 'get_executive_compensation', leaving a small disambiguation gap.

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