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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description goes beyond them by disclosing the auth requirement ('Needs the user's Cotlet API key with access to this app') and the returned fields. It omits pagination/rate-limit behavior, but for a read-only list this is solid added context.

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 and generally tight, but the first two sentences restate the same idea ('companies (divisions) your account can work in' vs 'every division your account has access to'), which is mild redundancy in an otherwise efficient four-sentence block.

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?

For a zero-parameter list tool with no output schema, it covers purpose, return shape, auth requirement and integration guidance. Nothing critical is missing, though pagination behavior for accounts with many divisions is unstated.

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 no parameters, so the baseline is 4. The description correctly implies no input is required and instead documents the meaning of the output 'code' value, which is the only semantic an agent needs here.

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+resource ('list divisions/companies your account can work in') and describes exactly what comes back (code and name). It is immediately distinguishable from the other exact-online_* accounting tools, which operate on ledgers, invoices and relations.

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?

Gives clear downstream context: 'Use the code as the division parameter of the other tools' and explains the fallback that a missing division means the account's current division. This is strong actionable guidance, though it never states an explicit exclusion or names an alternative discovery tool.

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