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

With no annotations, the description carries the full burden, and it does disclose two real behaviors: the operation performs no writes, and incomplete baselines yield null interest savings rather than fabricated figures. That non-fabrication guarantee is genuinely useful and non-obvious. However, it says nothing about what constitutes an "incomplete baseline," what permissions or inputs are required, cost, or invocation constraints.

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?

Two short sentences, front-loaded with the core action and followed by the most important behavioral caveat; nothing is padded. The second sentence is slightly compressed to the point of obscurity, but it earns its place by preventing fabricated-savings assumptions.

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?

An output schema exists, so return values needn't be re-explained. But for a tool with a required, wholly undocumented "budget" argument and a sibling that may overlap, the description omits the input contract and selection guidance an agent needs to call it correctly.

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 0% across three parameters, so the description must compensate and largely fails. The required "budget" parameter has no stated type, currency, or format, "months" has an unexplained default of 600, and "start" is never mentioned; only the vague phrase "incomplete baselines" hints at how these inputs relate.

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 gives a verb and a count ("Compare four strategies") but never names the strategies or the domain, so the agent must infer from siblings (list_debts, simulate_plan) that these are debt-payoff strategies. It also does not contrast itself with simulate_plan, which sounds like a near-neighbor, leaving selection ambiguous.

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?

"without writing" implies a read-only comparison versus some mutating alternative, which is a faint usage signal. There is no explicit when-to-use, no when-not-to-use, and no named alternative despite simulate_plan being a plausible competing choice.

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

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

No annotations are supplied, so the description carries the full burden; it does disclose that amounts are integer cents, which prevents unit errors. However, it does not state that the operation is read-only (only implied by "Read"), whether it returns all debts or one, or anything about pagination or failure modes.

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?

Two short sentences, front-loaded with the resource fields and finished with the unit convention; nothing is padded. It is efficient, though the terseness edges into under-specification of scope rather than waste.

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?

With zero parameters and an output schema present, the description need not explain return structure, so the bar is low and it mostly clears it. Still, it leaves open whether this returns a single debt or the full list, and "contract assumptions" is unexplained, which matters for an agent deciding between this and upcoming_payments.

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 zero parameters, so the baseline is 4. The added note that amounts are integer cents is genuinely useful unit context that the empty schema cannot convey.

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 gives a specific verb ("Read") and enumerates the data fields returned: principal, assessed charges, retained fees, contract assumptions. It is clear what the tool surfaces, but it never states that it returns a list of debts (as the name implies) or how it differs from siblings like upcoming_payments, so an agent cannot fully discriminate on description alone.

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?

There is no when-to-use guidance, no mention of prerequisites, and no reference to the sibling tools (simulate_plan, compare_strategies, record_payment, upcoming_payments) that an agent must choose between. Usage must be inferred entirely from the field names.

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

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

With no annotations, the description carries the full burden and does substantial work: it discloses that this mutates local state (principal reduction), that no external money movement occurs, and that retries should reuse an idempotency key. It leaves gaps on permissions and whether an entry can be reversed or corrected afterward.

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 tight sentences with no filler, and the core behavior plus the safety-relevant scope limit are front-loaded. The interest clause is dense and slightly opaque without domain context, but nothing is redundant.

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?

An output schema exists, so return values need not be explained. For a six-parameter mutation tool with zero annotation coverage, the description covers the key surprises (no external transfer, idempotency, interest semantics) but omits edge behavior such as overpayment, validation failures, and reversibility.

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 0% across six parameters, so the description must compensate. It adds real meaning for the two least-obvious ones (interest as a replacement for estimated newly assessed finance charges, and idempotency_key for retries) but says nothing about date, note, amount, or debt_id semantics.

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 ('Write an actual payment journal entry') plus the resulting effect ('reduce local principal'), and immediately delimits scope with 'No external money transfer'. That scoping clause separates it cleanly from sibling tools like simulate_plan and compare_strategies without needing to name them.

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 contrast between 'actual' payment and the simulate/compare siblings, and the retry instruction ('reuse an idempotency key on retries') is actionable. However, it never explicitly says when to prefer this over simulate_plan or what preconditions must hold (e.g. debt must exist locally).

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

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

With no annotations supplied, the description does carry useful behavioral weight by explicitly declaring 'Does not write or pay money', which establishes a read-only, non-mutating profile. However it does not explain what 'bounded' means in practice (truncation or horizon limits), whether the projection is deterministic, or what the simulation assumes; 'months' defaulting to 600 hints at a cap that is never described.

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 short sentences with the core operation front-loaded and the strategy enumeration immediately after. The word 'bounded' is the only genuinely underspecified term that survives compression.

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?

An output schema exists, so return-value structure need not be described, and the read-only safety profile is covered. For a simulation tool with five parameters and a 0% schema coverage, though, the meaning of order, start, and months—and what the 600-month bound implies—is a real gap.

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 0%, so the description must compensate; it does so for two parameters by clarifying that budget is in major currency units (not cents) and by enumerating the legal strategy values, which the schema leaves as an unconstrained string. It says nothing about order, start, or months, leaving three of five parameters undocumented in both places.

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 concrete verb and resource: reads a bounded monthly payoff projection, and names the four supported strategy values. It does not explicitly distinguish itself from the sibling compare_strategies, which likely produces similar strategy comparisons, so differentiation is left to inference.

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?

There is no statement of when to call this versus compare_strategies, upcoming_payments, or list_debts, and no stated prerequisites or exclusions. The agent must infer usage from the tool name and the word 'projection' alone.

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

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

With no annotations, the description carries the behavioral burden; 'Read' implies a non-mutating operation, and the description adds useful context that results are estimated and adjust for actual payments already recorded. However, it does not disclose permission requirements, rate limits, or other operational constraints. Since an output schema exists, return format does not need to be covered here.

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?

The description is a single front-loaded sentence with no redundant wording. It states scope and behavior efficiently and does not waste the agent's attention.

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 tool is simple with two optional parameters, and the output schema covers return values. However, because schema coverage is 0% and the description does not explain 'as_of' or the default day window, an agent cannot fully understand parameter behavior. It is adequate for a low-complexity read but has a clear gap.

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 0%, so the description needs to compensate, but it does not. It mentions a 0–366 day range that map to the 'days' parameter, but never names or explains that parameter, and it does not mention 'as_of' at all, including its default null behavior. This leaves both optional parameters substantially undocumented.

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 gives a specific verb and resource: 'Read estimated upcoming minimums' within 0–366 days. It clearly communicates that the tool estimates upcoming payment minimums and accounts for payments already recorded. It does not explicitly distinguish itself from siblings such as list_debts or simulate_plan, so it falls short of 5.

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 description implies usage by stating what it reads and the time window, but it gives no explicit when-to-use guidance. It does not mention alternatives like list_debts or simulate_plan, nor does it state when this tool should not be used. This is minimally adequate but leaves routing decisions to inference.

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