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 genuinely new behavioral context by enumerating the returned fields (id, name, role, add/change permission, enabled features, NZ tax year), which the annotations cannot convey. It stops short of noting empty/error cases, so a 4 rather than 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 the verb and resource, then the definition, then the return fields, then the routing instruction. The mid-sentence enumeration of return fields is dense, but every clause carries unique information; only the parenthetical feature examples could be trimmed.

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 no output schema, the description carries the full burden of describing return values and does so thoroughly, plus it supplies the critical cross-tool ordering rule. Nothing an agent needs to call this zero-parameter tool correctly is missing.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter semantics to add. The description correctly avoids inventing inputs and instead explains the payload's structure.

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 (Lists) and a well-defined resource (the taxapp organisations this connection covers), and even defines what an organisation is. The scope 'this connection covers' clearly separates it from the many list_* siblings that enumerate contacts, properties, expenses, etc.

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?

Explicitly directs the agent: 'Call this first: every other tool needs organisation_id when the connection covers more than one organisation.' This gives both the ordering constraint and the condition under which it applies, which no sibling tool states.

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