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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuine behavioral context beyond that: the no-argument mode returns a global summary, the ticker/slug mode returns a localised neighbourhood with depth 1-2, and it names the edge types (board-seat and shared-director). It does not note any cost or rate-limit behaviour.

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 sentences, front-loaded with the resource identity followed by the two modes and the usage triggers. Dense but every clause carries information; only minor trimming would be possible.

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 not be detailed, and the description nonetheless sketches them. It covers both modes and usage triggers. The one gap is ambiguity when both ticker and slug are supplied, but for a 3-param read-only tool this is largely complete.

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 the baseline is 3, but the description earns more by explaining the mode switch: absent parameters yield the global summary, while ticker or slug recentres the graph on a company or director. That conditional relationship between parameters and output is meaningfully beyond the per-field 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?

The description gives a specific verb and resource ('NZX director/company interlock knowledge graph') and enumerates the concrete outputs: Louvain community clusters, power broker rankings, and network statistics. It distinguishes its two operating modes clearly, but never differentiates itself from close siblings like get_director_network, get_network_intelligence, or get_entity_graph, which an agent must disambiguate.

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 provides an explicit when-to-use list ('board interlocks, director networks, power brokers, most connected directors, governance communities, or who a company's board is connected to'). There is no when-not-to-use guidance or named alternative, but the positive triggers are concrete and task-oriented.

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