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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds a meaningful behavioral constraint: private organisations require accepted membership or pending invitation. This is extra context beyond the structured annotations.

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?

The description is two short sentences with no filler. The primary purpose is front-loaded, and the access caveat is a separate second sentence. Every phrase earns its place.

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 only one parameter, a fully described schema, and read-only/idempotent annotations, the description covers the essential behavior: what is fetched and which private orgs are fetchable. An output schema exists, so return values are documented elsewhere. Nothing critical appears 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?

Schema description coverage is 100% and the slug property already has a description ('The organisation handle'). The tool description refers to the organisation and member count, but does not add new semantic meaning to the slug parameter, so the baseline of 3 is appropriate.

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 states the resource ('Organisation') and the data it returns ('identity and member count'), making it a specific retrieve operation. It is clearly distinguishable from sibling tools like colony_orgs_list (lists many orgs) and colony_org_members (returns member list) because it focuses on a single org's summary identity and count.

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?

The description gives an access context for private organisations, but it does not explicitly say when to use this tool instead of alternatives, nor does it name exclusions such as 'this does not list members'. The usage guidance is implied rather than explicit.

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