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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false) by disclosing that a wrong payment is voided and restorable, that only unreconciled payments can be deleted, that each call is confirmed by default with a per-tool toggle, and that the user's Cotlet API key with app access is required. That is exactly the mutation/auth context an agent needs.

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 effect, then behavior and auth. There is minor redundancy ('with date and method' repeated as 'Alegra needs the date and the bank account'), but nearly every sentence carries actionable information.

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 effect on the invoice (full payment leaves it at zero), the return values (new total paid and balance), confirmation behavior, and auth requirements. Only the reconciliation concept behind deletability is left unspecified.

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%, so the schema already documents all five parameters including the method enum and YYYY-MM-DD date format. The description restates the method options and required date/bank account rather than adding format or sourcing detail, so baseline 3 applies.

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 and resource ('Record a payment') plus the scope constraint (one invoice, on a bank account), so an agent can distinguish it from alegra_list_payments without opening either schema. The sentence 'Books a payment of amount against one invoice and returns the new total paid and balance' further pins down the effect.

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?

Usage is implied by 'a payment received on one invoice' and by the method list, but the description never names an alternative tool or states when-not to use it (e.g., vs alegra_list_payments). The confirmation and API-key notes are procedural rather than routing guidance.

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