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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds the useful scope fact that results carry current board seats, but says nothing about pagination behavior beyond the limit param or how current the data is.

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 tight sentences: purpose first, then the acronym glossary that makes the domain readable, then the filter surface. No filler and everything is front-loaded.

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?

With an output schema present, return values need no explanation, and all four params are documented. The description covers what the tool returns and how to narrow it; only the relationship to the many adjacent director/board tools is left unaddressed.

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%, so all four parameters are already documented in the schema. The description restates the filter axes (designation, ticker, name) and spells out the valid designation tokens, adding little beyond what the schema's designation enum list already supplies.

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?

The description names a specific verb and resource (get IoD-designated directors on NZX boards) and defines the four designation types (CFInstD, CMInstD, CDir, MInstD), which makes the scope concrete. It does not explicitly contrast itself with close siblings like get_board_credentials, get_directors, or get_director_detail, so an agent must infer the boundary.

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?

It states the available filter dimensions (designation level, ticker, director name), which implies how to narrow results, but gives no explicit when-to-use vs. when-to-use-an-alternative guidance. Nothing tells the agent why it would pick this over get_board_credentials or get_prohibited_directors.

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