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

The description adds behavioral context beyond the annotations: 'Record' signals a write operation, '$0.10' discloses cost, 'API key required' discloses auth needs, and external_id idempotency is explained. It also reveals the alias relationship to log_transaction with specific type and direction values. No contradiction with annotations exists.

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?

Three sentences, each earning its place: purpose, alias semantics, and idempotency/cost/auth. Information is front-loaded with the core action first and no redundant restatement of the tool name.

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?

The description provides key operational context such as source categories, alias behavior, external_id idempotency, cost, and auth, and an output schema exists. However, with 11 parameters and minimal schema descriptions, many optional parameters remain undocumented, so the overall picture is adequate but has clear gaps.

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 only 18%, so the description carries the burden of explaining parameters, but it only meaningfully adds semantics for external_id (Stripe/Gmail idempotency). Other parameters like source, merchant, person_id, payment_method, currency, and date are left without guidance, leaving the agent to guess at valid values.

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 opens with a concrete action and resource: 'Record money received' and lists real source examples (Stripe, refunds, payroll, Venmo). It also distinguishes itself by stating it is an alias of log_transaction with type=income and direction=from, making the tool's role clear relative to sibling tools.

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 first sentence gives clear context for when to use the tool: incoming money from specific channels. The alias statement and external_id idempotency guidance further clarify usage, though it does not explicitly name alternatives like log_expense or state when not to use it.

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