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

Annotations already cover read-only, idempotent, non-destructive behavior, and the description adds real value beyond them: disclosed return content, the removed-case response with date and reason, the [quoted]...[/quoted] prompt-injection warning, and citation format. This is exactly the behavioral context structured fields cannot carry.

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?

Content is front-loaded with the core 'get by id' purpose, and each clause (returned fields, removed-case handling, injection warning) earns its place. The citation template makes the middle dense and run-on, slightly hurting scannability but not enough to be wasteful.

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 no output schema, the description carries the full burden and does: it enumerates returned fields, describes the removed-case shape, and provides the exact citation form. Nothing an agent needs to call or interpret this tool is missing.

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% and the single id parameter is already documented with type, maxLength, and the FIN-S001 example. The description's id example repeats the schema, adding little syntax or format detail beyond it, so the baseline 3 applies.

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 ('Get one real case by its id') and enumerates the returned fields, clearly distinguishing it from the sibling find_real_cases, which is a search rather than a direct-id lookup. An agent can tell exactly what this tool does without opening the schema.

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 'by its id' framing plus the removed-case instruction ('say so and do not describe it') tells the agent how to handle both normal and edge-case results. It stops short of explicitly naming the alternative (find_real_cases) or the condition that would select it, so it is clear context without full routing guidance.

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