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

Annotations already declare readOnly=false and destructive=false, but the description adds real context beyond them: it returns the card ID, a card cannot later be converted from customer to supplier, and no confirmation is requested because the record reaches no one and is deletable. Auth requirements are also disclosed. It stops short of describing idempotency or error behavior.

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 purpose and return value, and each sentence carries distinct information (naming rules, irreversibility, auth). The redundant 'MYOB:' prefix and slightly awkward phrasing ('It reaches no one') cost it the top mark.

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 mutation tool with no output schema, it covers the essential ground: return value, required auth, the naming decision, and the non-destructive behavior. It could say more about failures or duplicates, but nothing critical for correct invocation 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?

Schema coverage is 100%, so the baseline is 3, but the description adds a decision rule for the mutually-exclusive name parameters (company_name for a business vs first_name+last_name for an individual). This clarifies the conditional requirement beyond the raw field descriptions.

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 (Add/Create) and resource (customer card) with the return value (card ID), clearly distinguishing it from read siblings like myob_list_customers and from myob_create_invoice. An agent can tell what it produces without opening the schema.

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 invocation context: pass company_name for a business or first_name/last_name for an individual, and requires the Cotlet API key with access to the app. It does not name an explicit alternative tool or a when-not-to-use case, so it falls short of a 5.

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