Add a document timestamp (PAdES B-LTA)

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

Even though annotations mark readOnlyHint=false, the description goes far beyond that: it discloses exact behavior (append over whole document, omitted fieldName auto-naming, TSA dependency, status/imprint/nonce checks, sandbox output behavior, and the SECURITY_VIOLATION risk when the sandbox is unconfigured). It does not contradict the provided annotations.

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?

Every sentence in the description is dense and purposeful: scope, procedure, failure mode, configuration dependency, security checks, and constraints are all covered without fluff. The content is compact yet complete for a five-parameter tool.

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?

Given the tool complexity, the annotations, the 100% schema description coverage, and the presence of an output schema, the tool is both internally complete. It covers when to use, ordering relative, constraints, configuration environment, output modes, and security-specific behavior.

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%, so the baseline is 3, but the description adds meaningful semantics for fieldName: omitted values produce DocTimeStamp1, 2, ... and colliding with a signed field fails. It also adds value by tying placeholderBytes to TSA certificate chain size in the frontend conceptual model.

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 ('append an RFC 3161 document timestamp') and names the precise resource (/DocTimeStamp, ETSI.RFC3161). It clearly separates this from sibling tools by calling it 'Ladder step 4 after add_ltv' and mentioning verify_pdf for verifying its signature.

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 gives explicit usage context: it must be run after add_ltv, should be re-run before the TSA certificate expires, cannot be applied to encrypted PDFs, and fieldName collisions with signed fields fail. It also states the condition under which the tool is unavailable (TSA_NOT_CONFIGURED).

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