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

The description says 'Bumps version' and describes an optimistic concurrency check via expected_version, implying that repeated identical calls change state (version number) and can fail with conflicts. This directly contradicts the annotation idempotentHint=true, which suggests the operation is safe to retry without side effects. This is a clear annotation contradiction, so the score is 1 per rubric.

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 long but every sentence earns its place. It front-loads the primary purpose, then adds essential behavioral detail (merge semantics, version bump, non-changes) without redundancy. The structure helps the agent quickly grasp what the tool does and what to be careful about.

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 output schema and annotations, the description covers all important operational aspects: it specifies ownership, workflow context, what is not changed, deletion semantics, merge behavior, and concurrency. It also references sibling tools (create_report, publish_report) for guidance. This makes the description complete for a complex update tool.

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 schema covers 100% of parameters, so the baseline is 3. However, the description adds significant semantic detail beyond the schema: citations are MERGED (first claim wins), remove_section_ids is required to express deletion, and expected_version produces a version_conflict error without writing. A minor gap is that it doesn't explicitly mention title/abstract can be updated in the same call even though sections is required, but the schema already documents those fields.

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 opens with a specific verb and resource: 'Replace one or more sections of an existing report owned by the caller.' This clearly distinguishes the tool from siblings like create_report, publish_report, and delete_report, and it specifies the scope of what can be replaced.

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 explicitly states when to use the tool ('authoring workflows where the agent's first draft (create_report) is refined by additional analysis before publishing'), and it names an alternative for excluded actions ('use publish_report' for price/tier/visibility changes). It also clarifies when not to use it implicitly by listing what it does NOT change.

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