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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=true, so the safety profile is clear. The description adds valuable behavioral context: the cancellation is a request ('Solicita'), the result may be 'pendiente' if receiver approval is needed, and it operates on an already-timbrado CFDI. This goes beyond the annotations by explaining the asynchronous/pending nature.

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, concise sentence that front-loads the core action and includes the most important behavioral nuance (pending status). No wasted words.

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 cancellation tool with full schema coverage and annotations covering safety, the description is nearly complete. It explains the pending status and the SAT context. It could mention that motivo=01 requires folioSustitucion, but the schema already covers that. No output schema exists, so return values are not specified, but the description's mention of 'pendiente' status partially compensates.

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 three parameters. The description adds no additional parameter-level meaning beyond what the schema provides. Baseline 3 is appropriate since the schema does the heavy lifting.

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 clearly states the action ('Solicita la cancelación de un CFDI ya timbrado ante el SAT') and the specific resource (CFDI). It also distinguishes itself from siblings by focusing on cancellation, while siblings handle creation, listing, and balance queries. The verb 'cancelar' is specific and unambiguous.

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 when to use this tool: when a CFDI is already stamped and needs cancellation. It also mentions the pending status when receiver approval is required, which is a key usage context. However, it doesn't explicitly state when NOT to use it or name alternatives (e.g., use timbrix_listar_cfdi to find the UUID first).

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?

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds valuable context beyond that: the scope is the current calendar month in Mexico City time, the response includes a reset period, and the critical enterprise caveat that cfdiIncluded/cfdiRemaining are null, not zero, with explicit instructions not to report 0 timbres.

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 sentences with zero filler: the first front-loads the core functionality and timeframe, the second is a tightly-scoped edge-case warning. Every sentence earns its place.

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?

Even without an output schema, the description gives the essential return semantics: usage vs limit, reset timing, and the null-values caveat that prevents misreporting. An agent has everything needed to call the tool and interpret the result 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?

The input schema has zero parameters, so the description has no parameter behavior to document. Per the rubric, a tool with 0 params gets a baseline of 4; no further param info is needed.

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 states the exact verb ('Devuelve') and resource (CFDI timbrados in the current calendar month against the plan limit, plus the reset period). It clearly distinguishes from sibling tools like timbrix_crear_cfdi_ingreso and timbrix_cancelar_cfdi by being a read-only status query.

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 full purpose makes the usage scenario obvious: an agent should call this when it needs current CFDI stamping usage against the plan limit or the period reset time. It does not explicitly name alternatives or state when not to use it, but confusion with the mutation/list siblings is unlikely.

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?

Annotations already indicate it is not read-only (mutating), not idempotent, and not destructive. The description adds the return format (UUID, XML, status) but does not disclose side effects, permission requirements, or irreversible consequences. It does not contradict annotations; the added value is modest, so a 3 is appropriate.

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 two sentences with no filler, front-loading the core action and return values. Every sentence contributes meaning, and it is appropriately sized for the tool's purpose.

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?

Despite the tool's complexity (15 parameters, nested objects, a confirmation threshold flow, timezone-sensitive date handling), the description provides only a minimal overview. It does not mention the `requiere_confirmacion`/`confirmado` workflow or the date timezone pitfall, which are critical for correct invocation. With no output schema, the description should summarize these to guide the agent; it falls short.

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 high (73%), and many parameters have explicit descriptions (e.g., date timezone warning, confirmation flow fields). The description itself adds no parameter-level detail beyond what the schema already provides. Baseline 3 is correct when the schema carries the documentation burden.

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 states a clear, specific verb ('Timbra' = stamps) and resource ('CFDI 4.0 de tipo Ingreso') and explicitly lists what it returns (UUID, XML, status). This distinguishes it from sibling tools that cancel, list, or check balance, so an agent can identify it unambiguously.

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 it is for creating/stamping income CFDI but offers no explicit guidance on when to use it versus alternatives, nor any prerequisites (e.g., configured organization) or conditions for use. Since siblings perform different actions, the lack of exclusions is acceptable, but the description does not add usage context beyond the action itself.

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?

Annotations already communicate read-only, idempotent, and non-destructive behavior. The description adds meaningful behavioral context beyond those annotations: results are restricted to the configured organization and are sorted most recent first. No additional side effects, rate limits, or response details are disclosed, but the safety profile is well covered.

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 filler. It packs the resource, scope, ordering, and filters into a concise statement that earns its place.

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 simple list operation with annotations covering safety, the description is mostly sufficient. However, with no output schema and no mention of pagination semantics, the documentation is not fully complete for an agent needing to use paginated results correctly. The core purpose is clear, but the page/limit handling is left to inference.

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 clarifies that 'type' and 'status' are optional filters, but it does not explain the pagination parameters 'page' and 'limit', nor the meaning of the enum values ('I', 'E', 'T'; 'vigente', 'cancelado'). This leaves half the parameters semantically underdocumented.

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 uses a specific verb ('Lista') and a clear resource ('CFDI timbrados'), plus the organizational scope and ordering ('más recientes primero'). It also names the optional filters, making its purpose distinct from the sibling mutation and balance 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 description implies usage: it is a read-only listing tool for the configured organization's stamped CFDI. However, it does not explicitly state when to use this tool over alternatives or when not to use it, leaving selection to inference from the tool name and siblings.

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