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

Annotations already declare a non-read-only, non-destructive, closed-world mutation, so the safety profile is covered. The description adds one genuinely useful behavioral fact — that any tenant id in the arguments is ignored and the caller's tenant is always used — but says nothing about duplicate handling, idempotency, or what a successful open returns.

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?

Three short sentences with the scope constraint front-loaded and no padding. The middle sentence ("Same record as New file") is the only one of questionable value given it names an internal concept the agent may not resolve.

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?

A creation tool with no output schema should at minimum say what comes back (e.g., the new case id) so the agent can chain into read_case or walk_credit_file. Combined with four params at 25% coverage and no required-field guidance, an agent cannot confidently construct a correct call from this description.

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 only 25% (just the optional `id`), and the description explains none of email, source, or legalName, nor what happens when all are omitted since nothing is required. Worse, its one parameter-related claim concerns a "tenant id in the arguments" that does not exist in a schema with additionalProperties=false, so it cannot guide actual argument construction.

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+resource ("Open a case") and scopes it to "the caller's tenant", which is meaningful. The cross-reference "Same record as New file" gestures at equivalence with a UI action but assumes the reader knows what "New file" is, and siblings like read_case are not contrasted.

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?

No statement of when to call this versus read_case, chase_missing_documents, or start_underwriting_package, and no prerequisites (what must exist on the tenant before a case can be opened). Only an implied usage from the verb "Open".

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