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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: an authentication requirement ('Requires signing in to FundingTracker'), the data provenance (payment terms in FundingTracker), and that values are estimates rather than actuals — all useful for interpreting results.

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?

A single dense sentence that front-loads the action and scope, then qualifies the source and the auth requirement. No filler, though the clause chain ('by date and by advance, estimated from ... the same schedule as ...') is slightly heavy.

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 one-parameter read tool with no output schema, the description covers the essentials: what is returned, how it is grouped (by date and by advance), the estimation basis, the default window, and the auth prerequisite. Only the exact response shape and empty-result behavior are left unstated, which is minor here.

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% and the 'days' parameter is fully documented with bounds and default in the schema. The description only restates the default window ('30 by default') and adds no format or edge-case detail beyond the schema, so the 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: 'List the debits expected over the next days ... across the signed-in user's open advances, by date and by advance.' The phrase 'estimated from the payment terms recorded in FundingTracker' implicitly separates it from list_my_bank_debits (actual bank debits), but it never names that sibling, so differentiation is inferential rather than explicit.

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 context is implied by 'the same schedule as the dashboard calendar' and the sign-in prerequisite, which tells the agent this is a forecast view. There is no explicit when-to-use/when-not guidance and no named alternative for cases where the agent wants actual posted debits.

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