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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so safety is known. The description adds significant behavioral context: it details the output structure (cross-class records with document_number, title, dates, binding_status, rendition URLs, plus last-changed date), explains deletion records, and states the 'only surface that reports removals' behavior. It also clarifies pagination needs. No contradiction with annotations; the description enriches beyond structured fields.

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 thorough but every sentence earns its place. It opens with the core purpose, immediately differentiates from siblings, explains the application parameter, describes the output format, and closes with operational guidance. No redundancy; the structure is logical and front-loaded. Despite its length, it is tightly written and essential for correct invocation.

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 complex delta-sync tool with date ranges, deletions, pagination, and many application codes, the description covers all necessary context. It explains output fields, deletion semantics, links to ris_get_document for further retrieval, references ris_list_reference for valid applications, and notes pagination. Given the output schema exists, the description need not enumerate returns verbatim, but it still outlines them sufficiently. Nothing critical is missing for an agent to call this 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 coverage is 100%, with all six parameters having descriptions. The description adds extra semantic value by noting that 'application accepts every RIS application code listed by ris_list_reference topic applications' (linking to another tool) and explicitly stating 'One application per call'—a constraint not in the schema. It also re-emphasizes the exact-date semantics for changed_from. This goes beyond the schema's baseline without duplicating it.

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 tool's purpose with a specific verb and resource: 'Track every document added or changed in one RIS application within an exact date window.' It also differentiates from sibling tools by highlighting its exact-dated, deletion-aware nature versus the search tools' coarse, additive-only intervals. The role as 'delta-sync and monitoring primitive' further clarifies its niche.

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 is explicitly defined: 'the delta-sync and monitoring primitive for mirrors and watchers, and the only surface that reports removals.' It contrasts with search tools, advising that this is for exact-dated and deletion-aware needs, and provides operational guidance: 'One application per call; page explicitly for large windows.' The description effectively tells when to use this tool over alternatives.

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